planning on buying samson 8 piece drum mic kit, need help picking a mixer

There are some USB mixers by M-Audio with no latency problems at all. Try their website.
It honestly depends on what you want out of a mixer.
If it's purely for mixing live stuff, then any mixer with enough inputs would generally do.
Though if you're looking at doing a lot of recording then an audio interface or a mixer with direct usb (better with firewire) out would be best. The Allen and Heath thing would do the job. I've heard good things about them, though they are pretty expensive. Something cheaper would be something like the alesis io/26. It's firewire and made primarily for recording. Though Alesis do some good other mixers with direct usb/firewire outs that won't break the bank as much. Check out the website. Just hunt around and check out reviews, generally the best thing to do.
it would be cheaper to buy a mixer with usb/firewire than to have to buy a pci card with that stuff and a regular mixer.
Echoing other posts, if this is for live use, I think you'll do ok with those choices. If your goal is recording, then you should consider doing a bit more research before taking the plunge.

For my own 2 cents, I wouldn't pick either of those linked items for recording purposes. Instead, I would concentrate all of my efforts towards getting the best quality Mics and Pre amps that I could afford. A mixer may not even be relevant for tracking drums. Generally, you want to go from mic to pre to computer with as few extras in the way as possible.