ShopBot Desktop router up for the challenge?

[sanddrag]

You could do a Tormach Mill with a little bit of tooling for right around the $10k mark (barely). If you were going to buy it, you should buy it right from the source rather than from Little Machine Shop. You may want to look into the 770 and perhaps even the 440. They are cheaper (and smaller) than the one you linked. Do not forget about the cost of a stand and possible enclosure. These things are worth it. I'll be standing next to a Tormach mill and their representatives this week. Let me know if there's anything you'd like me to look at or ask them.

I cannot recommend the other two mills you linked. They are oddball Chinese machines, and I doubt you would be happy with them.

As for noise, a router would likely me MUCH louder than a mill, especially in aluminum. And yes, it is substantially easier to cut aluminum on a mill than on a router, but the router can make bigger parts, whereas the mill can make thicker and more precise parts.

If there's any possible way you can swing it in the budget, it would be hard to go wrong with a Haas mill. They just introduced the Mini Mill Edu yesterday. But, you would need space for it and power and air for it.