#1. For your TNT2 card, just download the nVidia Linux drivers. NVidia has now made it just about "dummy proof" to install their drivers in Linux, they provide the drivers as a script which you just run like so;
You'll find those here;
nVidia's Driver Location
#2. emu101k (sp?) drivers for the SB Live! cards have been out for quite some time now, I haven't had any problems getting mine to run on my server or my daughter's machine. Server runs Mdk 8.2, daughter runs Mdk 9.2. When I test-installed Red Hat 9 two weeks ago on another machine (w/SB Live!) it had it set-up and running ALSA OotB (Out of the Box). I started XMMS and it played fine and dandy. If you are talking about 4+ speaker support, I don't know about that, I've been using headphones on recent builds and kinda gotten away from speakers.............
#3. Go to Transgaming's website
and download Cedega 4.1 or/and Point2Play (gui frontend and installer for Cedega) and install those. Cedega is the new name for WineX. I'm a beta-tester for Cedega/P2P, and I have to tell you, its working pretty well. The only game I can't get working properly is No One Lives Forever 2
and I'm almost there with that. Just about all the other games I own, I can play with minimal tweaking and just about OotB. Here's a short list;
City of Heroes
(in fact, it runs so well, I can't tell the difference between Linux and WinXP)
System Shock 2
Jedi Knight2: Outcast
Thief I & II
(another one that runs so well I can't tell the difference)
Baldur's Gate I/II/all expansion packs
No One Lives Forever 2
There are also several games that support Linux natively, most notably, iD Software, the makers of Quake;
Quake II & III
(note: I think Q3 looks and plays better in Linux than in windows
Unreal Tournament & 2003
You can also try Transgaming's Unofficial Wiki site
for ideas to solve any problems you might have.
Just a note, with the TNT2, you will not be playing more recent 3D games, so don't get your hopes up.