I'm a little late coming into this conversation but may have a little input that will help. From personal experience, I always like to rebuild if possible when replacing heads. Your compression will go up a little and not knowing what shape the bottom end is in, you are taking a chance. Saying that I have known people to swap heads and have both good and bad results.
When you pull the old heads, it is easy to check the cylinders for wear or any ridge. Not to be too obvious but either push you towards a rebuild. If you can pull the pan, pulling a couple mains will show you the wear on the bearings.
From what you said above, it sound like the engine is in pretty good shape. Unless there is something unforeseen, you should be able to save the crank, rods and pistons (assuming you don't need to bore the cylinders).
Heads - many choices out there. 64cc Combustion chamber. Here is a link to Summit for some decent Edelbrocks. Cost - $879
https://www.summitracing.com/parts/e...make/chevrolet
Cam/Lifters - Also many choices. Here is a set for $175.
https://www.summitracing.com/parts/c...make/chevrolet
This is what us old guys used to call a 3/4 cam. Very streetable but will increase torque and HP an ok amount. You will be able to idle at about 700 rpm and have good vacuum.
Since you aren't building this for a lot of power, don't worry about getting forged rotating assembly. Total over kill. The 2 bolt mains that you have are also fine as it is doubtful you will be turning 6K+ RPM.
Other things I would use are true roller rockers, a good dual plane intake. 650 cfm carb, HV/HP oil pump. Decent 2 1/2" dual exhaust as well. If you don't have it swap the ignition to a HEI. Points suck and not many people know how to adjust them any more...
This setup should get you close to 350 - 400 HP. Much better than stock.
So this is just my opinion, I'm sure many others will correct any mistakes made. Good luck on this...