Just a thought... have you considered .co? It launches shortly, has a lot of money behind it.
This one (IMO) is launching a little different then other recent extensions.
.co is (kind of) already in use. What I mean by kind of is that there are already popular extensions that utilize .co as part of their extension.
For instance:
.co.uk, .co.in, .co.cc, .co.nr, .co.jp and so on.
The UK and IN ones are very popular from what I read. Even though .co is currently Colombia's country code its also recognized world round as the shorted term for Company or Corporation. Hence why .co.uk is for business companies and the same with the rest of the.
My point being that .co may be a better alternative to .us.
Just my opinion. At least it should be worth looking into.
Cheers