So my frame takes a 68 x 120 mm bb, what's a decent crankset or crank/bb combo. I'm looking for sturdiness to do tricks and jumps, any help is appreciated.

your frame does not determine spindle length...you need match the bb & the cranks

Ok my bad , so all I need to know is the 68 mm part then and then match it up to the cranks , any recommendations on brand etc.?

You probably want Cheap stuff, If you are going to beat it Up. 68 is the BB shell Width..

go see what your LBS Has .. a Generic, Origin 8* perhaps, a square taper BMX '3 piece'
with a long enough axle to get the chainline right.

since I cannot see squat, go into a Bike Shop and they can see what you have.

* dependent on what distributor lines they carry.

Thanks for the help, Ive gotten the bb taken care of, and took the crankset off an older redline bmx i had, so far so good. looking at wheels now..