Here's my recommendation!!
Squier PA system $230. Squier is Fender's discount brand and Fender products are generally quality stuff, so I'd trust this as well. Plus this unit itself rates well on every site I've seen it on.
The system is 80 watts/channel RMS, has a reverb effect built in, 4 channel inputs for mics and your CD&G player, 3 band EQ, patch points if you care to add on external effects, a sonic processor, etc. later. The speakers are 120 watt, 10" woofers, and have pole mounts (you should go ahead and pole mount them to standing height and you won't have to use as much volume and get higher perceived quality).
http://www.americanmusical.com/item--i- ... -o-2.html#
3 decent Samson mics with high gain patterns that will make your vocal stand out (I have these and they are going strong after 2 years) $49.00
http://www.samash.com/catalog/showitem. ... GroupCode=
Finally, dunno if you already have a player (there is not one integrated in that VocoPro system), but here is a player to finish the karaoke system $77:
http://www.karaoke.com/cgi-bin/WebObjec ... &key=41192
This one has a key changer and remote. There are mic inputs on the machine, but you'll want to use the mic inputs on the Squier mixing amp unit for better sound.
That is all you need minus hookup cables for a total of $356.00, and it is a PA system that you could upgrade in the future!!
Hope that helps...