I'm also using Mixcraft as a Midi Editor and Midi Recorder, because it's software the most similiar to GarageBand, which I'm sometimes using on iOS.
Wow! A live! I remember loving its built-in MIDI synth back in the day. Honestly though, get a modern sound card . A good compromise between games, sound quality, and price is the ASUS Xonar DX. Seriously, if you can afford $70-$80, then get it. It has native ASIO support, 7.1 channels through 4 analog plugs, or a single optical cable, 116db SNR (signal-to-noise ratio in case you don't know which I'm sure you do lol). It's pretty clean sounding, a hell of a lot more than my audigy 2 that I upgraded from. I'd imagine it'd be a bigger difference from a SB Live.
Now if you're worried about MIDI soundfont configuration, get 'BASSMIDI driver'. It's a MIDI soundfont configuration utility for all versions of windows that overrides the default barf inducing windows soundfont. It's what I use to assign my Pokemon soundfont. And it does support all the MIDI Controller codes. It only loads .SF2 files though.