This web site is among the simplest I have ever encountered. Basically amounts to a list of available notes (many of which are up for auction on eBay), with a link to a single photo. The photos are usually of good quality (perhaps flat bed scans) of the obverse only. Descriptions contain more than average amounts of information, and are perhaps a bit too glowing in terms of grade. "Gem crisp uncirculated" is used on a number of the notes, for example.
I have not purchased from this seller, and it is not immediately apparent how one would do so from their web site. I suppose you would call them on the phone or e-mail them, but that is just a guess.