You won't be bending your own pipes. Buy a quantity of various bends, elbows and flanges and go from there. Cut them to length and start tacking them together how you like. Once you get everything tacked and looking good, then go back and fully weld everything, recheck fitment along the way since the pipes move during welding.
The only boots I like in the system are at the intercooler inlet/outlet. If you can, use v-bands everywhere else. Smallest I use is 3.5" for the hot pipe and charger to charger boost tube. 3" Intercooler piping is fine. I don't even bother with trying to fit a 5" downpipe. 4" is much easier to fit and work with.
I have bought flanges from all over the Internet then discovered Industrial Injection has them as well. I like their flanges the best so that's who I use. Their k31 flanges (s400/s500sx compressor outlet) work great with both 3" and 3.5" piping. They also have k31 flanges for 4" piping. They have aluminum and steel flanges for basically anything all the way up to 6".
Use a quality heat wrap also, don't buy the cheap $19 amazon stuff. I made that mistake and that stuff stinks bad when it gets hot, smells exactly like nitro RC fuel.
I've built basically 5 kits so far for my truck in a year. Take your time and do it right the first time. Don't rush through it like I did the first 3 times. I was never really happy with them until this last one, which is why I finally settled on powder coating.
Follow your vision patiently and it will be well worth it while saving you a lot of money.
