I don't think you will be disappointed there since Logitech generally sees a good line of products as well as speaker sets. They also have their own line up of keyboards and mice(cordless, trackball/ internet, multimedia keyboards etc.) to look over.
To replace an older MS Trackball Explorer corded 5 button type of stationaty mouse here,
I've been taking a good look at one of Logitech's cordless trackball models lately.
Newegg sees the best price on the THX Z-5300e set seen at
http://www.newegg.com/Product/Produc...nc.-_-36121121