On the cam, I would look at the Comp Xtreme XE268. That's what SOM put's in their assembled motors.
I wouldn't just put a set of heads on it. You could kill performance really quick with a bad set of heads. Like stock smog 76cc heads would ruin what you just built.
For about $400, I would put a set of vortecs or around $700 a set of S/R Tourquers. That will be a better move. And if you do the Vortecs, you'll need the intake for them. The S/R's use the old style bolt pattern.
A good dual plane RPM intake and 650cfm doublepumper and you'll be set.
If you want a lower cost head, and don't want to fork over big $$ now, find a good used set of doublehumps for now. But if they need worked, you may end up spending more than a new set of vortecs.
Good luck and happy building!
383 Speed-O-Motive stroker kit with Speed Demon 750, RPM intake,Proform HEI dist.MSD6a box,World Products Sportsman II heads, ported and polished with 2.02/1.60 valves,64cc,TRW forged pistons with 10.7:1 compression, Comp Xtreme 284 cam,Crane pushrods, Comp Cam 1.6 full roller rockers,ATI damper, 40 series Flowmasters, 4.11 gears with TH350 and 3000 stall.Powertrax NoSlip Locker