51 IFS, New rear end & Motor upgrade

[51panel]

OK, I Got the cash and am ready to go. Read alot of ideas on IFS swap on this site and others. Still would like more input on the major brand kits like Progressive, Heits, TCI etc. Do NOT want to scab on a clip. What kit is the best to set up for alignment and keep aligned? What will ride best? I don't want to go the air bag route. More cash than I want to part with and from what I have read will not improve my ride that much. Cost v/s Quality? Also one item missing from all info I have is the question of wheel offset. Don't the kits take that into consideration so you can get stock wheels off the shelf? Or do I need to think about special wheel offsets?
I am building this panel truck to be my daliy driver. Would like to drop from current (original) ride height only 1" to 2". Have plans to finish entire project over this winter and drive by May 1st. After IFS is tacked in and mounts installed am going to remove body and go at it ground up. This way I can flip over and weld right side up. Don't like sparks down my shirt.
Thanks to replys I found a dealer to get a new 350 SM block from. Also have a 450 trans ready to with el camio rear end. Thanks for the ideas and input