Depends on the size of the room.
But i dont recommend large speakers in any case. Their sound travels further than one expects, and causes neighbour problems.
The problem with surround systems is that the system is largely unused, because very few movies are made for 5.1 or 7.1 channels, and largely most games are not dolby ready. Which is a bigger problem.
So if you have money to spend, surely go for a 5.1 or 7.1 surround system.
Try the bose. I thought the sony ones werent good. I have a polk audio 5.1 with a denon. Depending on your budget, you will need to shell out for the 6 speakers in the setup($1500 onwards) and an additional $500 for the amp. I have a denon. But there's also the yamaha amps. Needless to say, you have some experimenting to do for your amp/speaker combination depending on your budget.
But if you are looking at computer surround speakers, some of them, creative for example, are surprisingly good. But i would go for the bose companion series for the kick you get out of them .