360 Engine Build Guidance (Boost Maybe?)

I 100% agree with boosting the current motor. I blew up 4 junkyard 5.3s figuring everything out. Granted it was all because of a certain coil type causing predetonation, however it would have really sucked to have scattered all the good parts. Also agreeing with TT5.9mag, you may not care for the LS which is fine, it was just what I had a lot of available to me, and it made sense in the horsepower per dollar argument even though I loved my 340. But everything else I did may benefit you with what you're looking to build for a street car as far as the chassis build and modern upgrades to make a good street driver that occasionally sees the strip. 780whp on 93 pump is fun as hell on the street too.

As Subcom said, you'll have a decent amount of money in your fuel system and engine management system as well. Unless you plan to go blow through carb, which is another can of worms that I'm sure a ton of guys can help with on here, you wont need a whole engine management system but there are still costs there like an ignition module that pulls timing per psi of boost etc. Good fuel and engine management is worth it on any build you want to put miles on though.

It will also help immensely if you can fabricate yourself. Not saying its impossible to do it if you can't, but just be prepared for that cost of the hot and cold side of the turbo setup if you're paying someone else. I highly recommend the 78/75 kit from VS Racing if you go turbo. Hundreds of guys are using it on the sloppy mechanics page that Matt Happel started and Matt worked with Viren building this kit. Its like $1300 for the turbo, intercooler, boots, oil supply and drain lines and universal intercooler piping. But you're quite a ways from there and this is just one persons recommendation.