Pull the heads and check the cylinder walls for wear. If they look good, check your bearings. If there's not too much copper showing
then just toss in some new bearings and gaskets/seals and call it a day. A cam is a good idea, I've posted the specs that work well with a mild rebuild in many other posts as well. A new timing chain wouldn't hurt but everything else can stay. On the heads, if you can get them ported that's a huge plus. I'd stick with stock valves and just upgrade the springs. In any case get the guides checked, replace the seals, and have a 3angle valve job done. Check your timing cover to oil pump contact surface where the rotors spin. If it is grooved or worn badly, replace the timing cover and pump. I believe any 3.8 timing cover will work fine but use only the high volume SC pump.
If the cylinders are not so hot then I'd pull it all down and put in new pistons and have the crank trued. Don't take any more off the crank than absolutely necessary. Then change all your sensors, port the exhaust manifolds, replace the HB and you are on your way.
The stock motor is plenty strong and other than rod bearing wear, I've not seen to many problems.