'70 Dart 392 Project; what direction?

Hey guys, been cruising the forums for a couple weeks now, enjoying seeing all the projects and been heavily using the search function. Have some questions though if you'd help a guy out! Sorry in advance for the long winded post.

Drove 1800 miles round trip a few weeks ago and picked up a beautiful '70 Dart swinger (will post some pics from my phone after this) in eastern California. Bought the car with no motor/trans, but "fresh" 12 year old paint though the car was never fully assembled after that. It's got the original /6 K member in it and a 7 1/4 rearend. Have all the glass (tinted already), headliner kit, carpet kit, trim pieces....etc Needs the bench seats recovered but a great starting point.

Anyways, I've since then acquired a 1970 Duster 4 speed A833/SB bell housing setup complete with the floor plan/trans crossmember and pedal assembly. As well as some V8 Torsion bars.
I also two weeks ago found a burned up 6.4 BGE engine. When I say burned up, the 2014 pickup it came from had a cab fire. It melted the intake cover and damaged a lot of the accessories. Price was right at $800 however so I snagged it. Got the heads dropped off at a local shop to be inspected and resurfaced, will be dropping the block off to be hot tanked this week as well, top of cylinders looked really good so hoping for just a re-ring and hone job. Also picked up an SRT8 complete intake with fuel rails/injectors/throttlebody. Owner of the intake said it has "6 wire" injectors which are bigger than the "4 wire" injectors... I still see a 2 pronged electrical connector so not sure what he's referring too...

So far my plan is to use the holley Midmount front cover/accessory package since the original accessories were trashed from the cab fire.

I've also got a cam/valvespring/VVT lock kit coming from MMX. Should be here this week. MMX has said that with a decent tune, headers and this Cam with the 9.5 compression ratio BGE Truck block that 450-500 whp is what I should expect.... crazy town, I was hoping for somewhere in the 375-400whp when I started this project.

First questions deals with the front suspension, this is a long term project (been waiting 17 years to pick up another mopar project, want to do things right). I have a box of front suspension parts from the previous owner for a front disk brake setup, haven't inventoried them however. FYI front suspension systems are probably the area that I need to improve my knowledge on the most! So please bear with me.

Option 1 for front: Use OE type suspension, swap to a V8 K member and TTI mounts (have a V8 K member at a friends), upgrade to the smaller borgeson power steering pump, remote oil filter setup, TTI headers, Holley cast aluminum oil pan, and figure out how to make the factory steering system work with the oil pan clearance issues for the 68-72 setup. Another option is to find and "upgrade" to the '73 steering system that has the linkages pointing "down" that will clear the oil pan. Then use my OE type disc brake conversion. I've been advised to atleast upgrade to adjustable tubular upper control arms to help brings things into alignment and improve handling, as well as gusset and reinforce my OE lower control arms.

Question: Has anyone run the mini borgeson pump with the holley midmount accessories and factory K member? Is it a no-go or will it be feasible? I can cut and reweld anything, so if some minor clearancing is needed than no problem. Even if it's not a "bolt in" guarantee.

Option 2 is to save up for a while longer and go with a complete HemiDenny front K member suspension/coilovers.... This seems like the most simple option, however it definitely isn't cheap especially with the disc brake/coil over/R&P steering setup. Long term when comparing costs it may just be the smarter route to go. Time is money and if I will continue to rework every component of the front suspension/steering system, then this is a favorable upgrade.

Option 3 is to use the QA1 tubular front K member and piece together the needed parts to complete the setup. I can TIG weld and I have a fairly complete cnc/manual machine shop that I run for my own business, so fabricating skills are there, however the knowledge of steering geometry and what is appropriate to adapt is what I don't know. Would this front K member combined with the factory torsion bars and steering linkages be a viable option? They say it's a "drop in" K member.

I've seen the R&P steering setups condemned on this board, and I've seen them praised.... Not sure what to think about them! Would adapting a Dakota or similar setup be a smart decision? That borgeson pump isn't cheap... but my wife will sometimes drive this car and power steering is a must, or at least "low effort" steering is a must.

Few random questions for the other areas of the build:

Megasquirt vs. Holley Dominator EFI, I've installed and have dealt with the MS platform before and am fairly confident in it. Does the holley system allow the same tunability as the MS system? Any preferences? Does the MS support the drive by wire TB?

Rear suspension/traction issues: How the heck can I expect to hook up 450-500 whp on the street? I'll be building my own rearend for the car, planning a minitub and likely offset spring shackles, along with 3:23 gears and a narrowed housing. Since the suspension will be modified heavily anyways, should I be thinking about going to a 4 link rear? Or can I run say the Hotchkis springs and a good shock setup?

I appreciate any info. It will likely be mid summer before I'm finished with the engine build and am able to start test fitting the drivetrain, so until then asking questions is the only way I know to start putting together a gameplan.

Mike