You only want 7-8psi, but you bought pieces for a 20psi setup.
What I see that is wrong.
-Downpipe, unless you buy the exact same manifold and turbo size it was designed for it will not fit.
-Bypass valve, why? You are going to chip your ECU anyway, its not an option.
-255 fuel pump, the stock one will do the job on dd at 7psi.
When you do a cheap turbo kit, you look for cheap pieces. Only parts that worth money is turbo, wastegate and for some ppl the BOV, but I think the ebay can do the job.
You will need to cut and reweld the downpipe I'm 90% sure of this. I hope your intercooler kit was designed to have the turbo on this side! I also hope that you can keep PS with it.
Get cheap injectors, you don't need over 450cc.