The 4.25" stroke kits, often called 512" kits, but really 505" with 0.030" overbore, are really popular. There are three standard piston dish size choices, flat tops, -17cc, and -27cc. and the smaller 2.20" connecting rod journal size makes the rods clear the block with almost no clearancing needed, except maybe around the oil pickup tube boss.
The 8-3/4" can handle quite a bit of abuse and should not be an issue unless your running quicker than 12.0. Some RedLine ShockProod gear oil will help protect the rear gears.
The trans can be rebuilt with some HD clutches and kolene steels. Get a 4-clutch front drum if the trans only has a 3-Clutch drum. Add a TransGoTF-2 Shift kit and transmission cooler. Make sure the driveshaft U-Joints are in good condition and add a driveshaft safety loop.
You may need some rear suspension help to prevent axle wrap?

Heads and cam will depend on power level you want.
Currently building a 505 stroker with Trick Flow 240 heads and a small solid roller cam. Not a low budget build, the cost of the recommend HS rocker arms really took a jump in price in the last few years.

Don't forget small stuff like HD motor mounts and/or limiting device so you don't rip the motor mounts apart.