I would vote drill if you can swing it.
As far as measurements for your sump, it is going to depend on your equipment. It will be tough to get a skimmer in a 10G if you are looking for one, and still have room left for a fuge, and leave sufficient volume for the return section. Remember as water evaporates out of the system, the return section is what will lower... so if you only have a gallon of water in the return, you could be looking a situation where your return pump runs dry pretty quick unless you use an auto top off system or top off every day.
What I would do is if you are going with a skimmer, decide which one you want, make the first section just big enough for it. The fuge in the middle should then be around 2/3 of what's left, and the last 1/3 is the return section. You also need to make sure you can fit your pump in the return section as well, though.