avery, like you said u dont have a ton of money to spend....so why spend a ton of money regearing those axles to 5.13s? swap in a 400/205 slipyoke and you are done...at most $500 + labor. you are going to easily spend $3k regearing and getting the 700r4. ask me how i know. Sh!t adds up quickly
thats the name of the game.
should be about the same length (plus u get rid of the 208 for a much stronger 205). you can do the labor yourself so thats free, only thing you would need is to have your front shaft lengthened. get the stock 400/205 crossmember (pretty cheap off here). thats far from $3k. what does smog have to do with a tranny? as long as its done correctly and clean, it shouldnt really matter in terms of a visual, they wouldnt know the difference even if they did care.

What is your next plan? Have you thought about getting a buddy and swapping the 700r4 yourself? Hardest part would be setting the tv cable so you don't burn the tranny.