Usagiya is great - I think they deal mainly with Keiun Naohiro (whose stuff is really nice, btw) for new swords. They won't take commissions, but they'll see about having a sword made within your parameters that'll still sell if you don't like it.
If we're going into American smiths...
I think Joe Walters is still a bit out of the game, as far as new stuff, and I know Howard Clark isn't taking orders for a long while (though his available page is updated now and again).
I have two Randal Graham blades - I'd put them up against anything else, but that's just me. Plus, he's still "getting back in the game," as he says, so he's very cheap, considering his skills.
Just to add someone whose stuff is affordable and still pretty nice and very custom, check out Walter Sorrells:
http://www.waltersorrells.com/blades/
Steve Schwarzer is also making some good stuff, fitted out by Wally Hostetter:
http://www.steveschwarzer.com/schwarzer-hostetter-1.htm
David Schlueter has also made some interesting stuff, though he's not taking commissions and only selling completed works now:
http://oddfrogforge.com/