because i didn't know he meant 59cm. i still think you need a 61cm at least but the only way to find out is to get a fitting on a fit bike.

and those other frames aren't frames, they're complete bikes that will be better for less money.

sputnik is a good bike too. if you want a custom build, go for it. just be prepared to spend a lot of money on something that is only as good as the ones mentioned, albeit spec'd to your liking. under 700 is fine but you can find better values around.

the platform / reload straps sound like a terrible idea, as do the riser bars. each are great for one specific thing... the risers only have one hand position which isn't great for going fast, and the platform pedals are comfortable but not necessarily good for long distances or tight corners.

threadless is great if it's fit before its cut. you can adjust a threadless just like a threaded but it requires reassembly or a fancy type of stem.

it sounds like your friend wants to build you a big bmx bike. that's great but the soma rush is NOT the frame to start with.