I would recommend that you get a separate modem and router. At least if one goes bust or is giving you a problem, you would then know which is the culprit.

A decent router preferably a wireless G would have sufficient signal if placed properly in at home. This linky might help you when it comes to the placement of the wireless router. http://www.wi-fiplanet.com/tutorials/article.php/3625796

As for brand name, Linksys and Belkin are two named brands I have used. No problems so far.

Hi,

I second that: get two separate units. I was thinking of getting a "all in one" solution, too, but these are a) hard to find and b) much more expensive. As uglyman said, two units also help with troubleshooting, which is very, very true.
I myself have a Linksys WRT54G (I bought it here, ca $70), which is a pretty basic, but robust device and easy to set up. Signal is pretty strong all through my house, so no worries here.

kengel