Soundfont's weren't invented by Creative, but by EMU (who were bought by Creative and are now their 'professional' soundcard brand) - I had a quick look at their product range to see if they still have legacy support for the technology and it looks like you can load up SF2s in their Proteus X LE software that they bundle with their cards:

http://www.emu.com/products/welcome.asp?category=505&

If the creators of the technology have switched to software only support I'd say it was more than safe to go down that route. As other people have said the most important requirement is a soundcard with low latency ASIO drivers.