I'm in the market for new computer speakers. Don't want to spend much, but I'll be hooking these things up to a SB Audigy Platinum. I have been referred to the JBL line, specifically the creatures, but I just noticed the invaders. I know it's hard to compare a 2.1 to a 4.1 system, but which would be better? Does JBL make an affordably priced 5.1 system?