Prolly late but ah well, somethin' I know...
1. No longer play video games, however there should be no noticeable difference when switching to a wireless connection. Faster IS better, but even a wireless-B connection (802.11b) connects at 11 MB/s, which is WAY faster than any residential internet connection. 802.11G is faster still, at 54 MB/s, I recommend spending a tad bit extra for the G, makes in-house file transfers much faster. 802.11 A is same speed as G, however operates at 5 Ghz as opposed to 2.4 Ghz for B/G, so there tends to be less interference if you have many cordless phones that operate in the 2.4 Ghz range.
2. Far as brand goes, any out there are okay, and people will start fights over which brand is "best"... fact is, they are all based off the 802.11 b/g/a standards, and as such, MUST be interoperable with like equipment (B must work with B, G must work with G, A with A, etc). They are typically backwards compatible with each other, and will operate at the lowest common speed (G card, B router = B speed; B card, G router = B speed; you get the idea) Brand choice is basically, whatever's on sale.
3. Red.
4. My recommendation, even though you already have a wired router, is to buy a new wireless router and ditch the one you have. You COULD go with strictly an access point, which WOULD get the job done, but honestly, cost is going to be the same, and you don't really want to have more of those damn bluish-purple and black boxes stacked than you really HAVE to. If you need more than 4 wired connections, get a switch, not a router (double-routing = abitch)
ayup.