It depends on your, realistic, useage of the speakers. Theres no point in paying for extra "power" if your not going to use it.
General rule of thumb.
Medium/Big room
bit RMS rating needed.
Small room
smaller RMS rating.
Loud usage
big RMS rating
quiet/normal usage
smaller RMS rating.
Also, look at reviews of the speakers. Search google or somthing for reviews.
I have the 5300`s and find them very good for gaming/DVDS/Music/Other Stuff.
I have the volume at about 60% in a small/medium sized room, and the quality is great.
If your buying them from a local retailer, then ask if you can try them out, to see what they`re like for YOU.