http://www.filebuzz.com/fileinfo/102535/ModPlug_Player.html
http://www.wavsource.com/sfx/sfx.htm

tons of sound wave sites out there . just have to look for them . Matt has a tutorial on sound editing in ut 99 on the server that works great .
If you do music to a .uax instead of a umx Better sound and can make it a larger file size with more then one song or sound files in it . 
Mattman is really good at it and {dFb} Pipe is also good with it . Can pm them and or the email links are in members list and can name search them with IM that they use , email and PM too 

So how is the server running? 
we are moving our servers right now to Atalanta , You should get a 25 ping on it . We also added a UK server and  German server and we are going public with a link to every map , mod , voice pack , skin , tools , etc .... to every thing ever made for ut99 ....Over 40 gig's of info for download .