There are some imported brands of knee mills that are worth looking in to in lieu of the Bridgeport name. Again, they're priced relative to their quality. You can look for Tree, Lagun, and Index. When looking for a used mill, alot of times you can get the collets, vise, and other tooling included.
Getting a variable speed head is a worthwhile investment as opposed to a belt-drive head where you have to manually change speeds and your speeds are limited.
Check out places like http://www.use-enco.com and http://www1.mscdirect.com for all of the support goodies. They sell machines too. You can spend a lifetime and a fortune stocking up on stuff to use.
If you're machining aluminum buy the low-price non-coated high speed steel cutters. If you're going to machine steels, buy the low-price non-coated carbide cutters, it'll be worth the extra money in time saved. There's no need for coated cutters if you're making one or two of anything.