I dont remember exactly what they charged me but I believe it was round $1000 for all 3 but i had couple extra things done, like blue anodized bodies. fronts are triple rate, rear is double rate. They'll set them up for ur weight, riding style and level. So when u turn one click, u can tell unlike stockers.
As far as a arms go...stock width is 49 in, lets say u do a set of walsh arms, when u change arms u should also change rims. Stock rims are 3-2 offset, with most aftermarket arms u should run 4-1 offset. And u would b exactly 50in...