Used parts... good idea? bad idea?

So I have begun saving for my rb25det to go into my 90 240. I am obviously going to be broke for the next 6 months. However, my car is going to need a lot of upgrades to be ready to handle the horse power. What used parts are okay to use and which ones are just a bad idea. We have lots of U-wrench it type salvage yards around here plus theres always ebay. I have done a lot of research up to this point just waiting to ask you guys this question so give me what you got.

Some parts in example I am looking into:
Spindles & Hubs 4-5 lug conversion
Brake and Rotor Upgrade
Fuel pumps & Lines
Coil Overs
VLSD and Half Shafts
All Body Parts
And anything else I might need that I should look into used wise or should definately stay away from.

I know a lot of people out there are dying to drift out their cars but dont have the money to buy factory direct. There are so many used options on ebay its hard to tell whats good and bad. Thanks again.

just make sure those parts are immaculate.. the rb25 will put out quite a bit of power so you don't want a $300 part with a small flaw to ruin a $6000 project.. for things like lines, it never hurts to upgrade to say steel braided..

Good call, do you know where I could or should get the steel braided lines, will my local shop carry them? I found a cool project for turning your 240 into a race car by using mostly used parts it's pretty enlightening.

http://www.sportcompactcarweb.com/tech/0211scc_projsilvia/

You can buy the stuff in different sizes and lenghts from Earl's (a Holley company), you can also buy all kinds of fittings and stuff.

Will a J-30 91' - '94 subframe bolt onto my '90 240sx

Fuel pump and lines, not the best Idea, buy one from Auto Z for a Z32, and upgrade to steel braided.