Having a high powerd sound card is'nt going to solve your problem but it is a step in the right direction. Keep in mind that info being shot into your computer has to be procesed on the input phase as well as the out put phase. Plus your tracking software has to process that info. All of this adds up and creates lantency or delays. Your going to need a comuper system that can process the info at a high rate. Computer wise have a Processor speed @ lest a 1ghz with a system bus of 300mbs and 1gig of menory, this is minimum. Next if your useing PC I hope your running windows XP. Next would be the software your tracking with. If you have the opition for ASIO audio drivers use it, these drivers are far superior to the WDM drivers. Another thing is to have two hard drives. One drive should have your OS and other sotware loaded on it while the other is setup to hold all your audio. Specs for your drive 80gb with a RPM of 7500 miniumum. Just remimber that the faster your system can process, store and then access your audio info the less latncey you will have.
Hope this helps