It depends, if I'm doing heavy typing, I'll line up G and H with the center of my monitor, but if I'm gaming or just browsing around, I'll line things up so WASD and my mouse are about the same distance from the center. It puts F9/F10 near the middle of my monitor, with a tenkeyless...
As for a keyboard without a numberpad, as long as you don't mind mechanical prices, there are quite a few options, you've got stuff like the PLU ML-87 at the cheap end, moving to Ducky, Leopold and Filco as the more expensive, and all the way up to the Realforce 86U / 87U at the high end. You can get a variety of different switches, everyone has their own personal favorite, so take some time, read through the wiki, and if possible, try some out in person.
Personally, I use a Filco tenkeyless with Cherry MX browns, but I also have a PLU ML-87 on the way, just to take a look at it. The ML-87 should run you under $100 shipped, and while it's lacking NKRO, it does supposedly have a fairly well optimized matrix for gaming around WASD. USB, with 3 options of switches, in black or white, and with or without key labels... Decisions, decisions...