Band saws - I can't speak to the utility of a bench top band saw, but I have the 14" Grizzly "ultimate 14" bandsaw" model with the 6" riser block. It is absolutely one of the best and most used tools in my shop. It will set you back about 3x as much as a bench top model, but if you can hold off and save the extra dough, I think it would be worth the wait and extra investment. I personally don't feel I will need or want to upgrade from this saw anytime soon.
Drill presses - I have a small 8" benchtop model that I paid about $35 for. It is a very handy tool to have, but it has its limitations. The main one being that with an 8" (swing) it only has about a 4" throat capacity, which prohibits drilling holes for tuneomatic bridges on most guitars. This was very frustrating for me , so I finally purchased this floor standing 34" radial drill press that can be adjusted to give a throat distance of 17".
Radial drill press
I think a bench top drill press can do most of the things you would want for guitar building, but I would try and get one with at least a 12" swing, otherwise you may not have the reach needed to drill some things like bridge holes in a body.
Oh yeah, as far as power, my bench top has only a 1/4 hp motor and is a bit underpowered. You can make up for some of this by adjusting the rpm and going slow. It only really becomes an issue when trying to use larger diameter forstner bits. This is a problem with the radial floor drill press also, which is rated at 1/2 hp. It is not a big deal for me though, as the power is adequate on both drills for 98% of what I use them for.
Good luck with your choices.