since ive hit bitcoin gold in the last few days ive set aside 2 btc to build me a new cruncher, that is roughly between 800-900$'s depending on current value of bitcoin so that is my budget
newegg takes payments in btc

i have a case, 750w psu's 500 gig sata hd's
basically i need mobo cpu ram gfx card(s)
with that budget whats the best cruncher u could build


my 2 main crunchers are the amd a8 3800/ati 6550 and my fx 8320 gt430's both of wich have open pcie slots , would i be better off just buying some nice gfx cards for those