Bicycle Mechanics - Cartridge Bearings for Hubs?

I want to replace the sealed cartridge bearings on my back up wheelset. It's a no-name brand that was made in Taiwan of mid grade parts. Are there any recommendations for a brand or type of bearing that might be a better or higher quality? Where can they be purchased? Thanks.

55/Rad

Look on the seal or lip of the bearing. There should be a cartride number. With that number you can go to a bearing wholesaler or small power tool shop or even a bike shop and get replacements. The bearings will run from decent at $7-10 to high grade at $40>

Better yet take the bearing or wheel with you when
you go the the bearing shop: look in yellow pages
under bearings. The counter guys can tell immediately
what you need, then the decision will be bearing grade
and what is in stock. There are very few really hard to
find bearings. If not in stock they are a day or three
away from the regional distributor. Avoid the cheapest
bearings. If you go to a bearing jobber, they will tend
to have good to really good and not have crap. Their customers are knowledgeable and have expectations as to quality. Secondary sources like LBS, Walmart, lawnmower shop etc tend to sell to the more price concious hence you may unknowingly be sold crap. Steve

Addendum: bearings from China are suspect, Taiwan, Japan, US or
European sourced bearings are usually ok. The Chinese can make
good bearings, but they are the leading suppliers of industrial trash
so the combo of low price and Chinese should lead you to look for
another supplier.