Decent handling susp setup?

1.00" min with the level of upgrades and what "appears" to be your objective.

You looking to do some track days and/or autocross? Are you looking for aggressive handling? Much more than just street cruising?

What size tires you thinking?

Have you driven it with any of the upgrades mentioned? Or in process of building or planning?

I'd go double pumper for the throttle response. I doubt this is a car you drive back and forth to work?

I'll second this. I wouldn't go less than 1", and actually having run 1" Just Suspension torsion bars on my Duster I found them to be pretty soft still. The 1.03" PST bars are a good option, hard to beat for the price and a good compromise for wheel rate if you're primarily looking at a street driver. 18's are pretty much the way to go if you want to go wider than 245 for tires in the front. If you stick with 245's you can run 17's if you prefer the look of a little more sidewall. If you set up the backspacing just about perfect you can run 255/45/17's, but you have to hit a pretty small "window" with the backspacing so rim choice would be limited if you wanted to run 255's. If you want to go any bigger than that you need the extra backspace the 18" rims provide because they bypass the outer tie rod clearance issues that come up with anything 17" or smaller. With a Demon and the stock rear spring locations you could run 275's on all 4 corners with 18" rims and the proper backspacing.

The carb is really a matter of what you prefer. Either will get the job done, the one you're most comfortable with is the best choice unless you're planning on being super competitive about things. I've run both, I've found the general stereotype holds true. The eddy's are a "take it out of the box, bolt it on and run it" type of affair on a lot of cars, where the Holley's tend to need more initial set up to get them right. But, the Holley's are very tunable if you know what you're doing, so a knowledgeable tuner should be able to get more out of them. Not as convenient as the Edelbrock's, even when I've had to make some initial set up changes on the Eddy's they're pretty much "set it and forget it". The Holley's seem to require a little more fiddling to keep them set up right, at least that's been my experience with the 750 double pumper on my 340. So they both have their pro's and con's, whichever you're most comfortable with is usually the best option.