GM TBI on my 1970 360 duster

ive been messing with GM TBI in 80's chevy trucks for a while now. Which means I have a bunch of spare parts and tuning equipment for these things. I almost have enough to build a complete system, if the inventory in my head matches my inventory on the shelf.

reason im looking at this is that im currently running an 850 double pumper that has been heavily modified. No choke, different air bleeds and idle passages, etc. I have problems with this carb, and have been seriously debating swapping it for an 800 CFM AVS from Edlebrock. at 400 bucks, i can probably build a TBI system for less, and have better drivability and economy to boot.

a few questions while i ponder this conversion:
1. Fuel lines. im currently running the stock 318 fuel lines size. i think its 3/16. might be wrong. i have no return line. Stock 70 tank and pickup. what do i do about the lines? is there a pickup that has a return line already built in, and then i can bend up a 5/16 feed line?
2. the car lays down 427 horse at the wheels. should i use the biggest throttle body i can get my hands on, or shoudl i go with a little smaller to keep air velocity and throttle response?
3. ignition. Currently im running an MSD box and rev limiter setup from an 80's winston cup car. Stock electronic distributor. The GM ECM can control the timing as well, so it would be stupid not to use it. any idea how to do this with a chrysler distributor?
4. should I? the car is built as a sleeper. looks all but stock at first glance. Very clean and uncluttered underhood and everywhere elso. Im worried that if i convert to EFI, all the extra wires and sensors will be a dead giveaway and ugly to boot. it aso only gets driving a couple of thousand miles a year. Mostly because it drives so bad.

anyway, goive me your thoughts.
Michael