@toolmanmike has the skinny on the Isky cam you'll want, I forget the model at the moment... E65?? or something like that.
If you have a '65 and earlier engine, then the 302 heads will allow you to use any of the standard LA manifolds as you mentioned, without a huge increase in chamber volume. I would not install larger valves, since 2.02s will require a bore notch, and the resultant valve shrouding sort of negates any improvement- I believe 1.88s are the largest you can go without notching. Stay with the thinnest head gasket you can find, and try to stick with a gasket with the smaller (non 340/360) bore size.
The factory 4 bbl. manifold was a single plane, so staying with a street oriented single plane will keep things looking stock. The Holley Street Dominator and Eddy 318 Streetmaster come to mind, with the Holley being my preference.
To keep the air cleaner height down, you may need to use a shorter filter element, and don't forget that the baseplate will need to be replaced in order to fit a carb with a 5 1/8 inlet. Most people just use the bottom plate off of a cheap aftermarket chrome 9 or 10 inch filter.
Also be aware that the 302s may end u causing some minor fitment issues with the stock driver's side manifold- the larger "emission style" exhaust pads interfere with the downleg of the manifold. I usually run a header flange between the manifold and the head to gain the needed clearance. Some people have gotten away with grinding the pad for clearance, but I have personally hit the water jacket with minimal grinding... junk head. Oh, and drill/tap the air injection ports to plug them while you're at it.
