Most usb keyboards only support 6 key presses at a time unless they do something funky. A PS/2 keyboard with diodes on every switch is the easiest way to make sure that every keypress will register correctly.
With that said I advise you look at the WASD v2, it has a very simple design (just a black piece of plastic, no flashy logo, no backlight, etc). If you use the ps2 adapter that comes with the box then you can press down as many keys as you want and they will all register correctly.
There are other mechanical keyboards out there with NKRO and various levels of minimalism. I know a lot of people here tote that Filco's have great build quality and design. If you want there are also some custom cases on the market for them.
Note: NKRO means that any amount of keys can be pressed at the same time and register correctly. This is the same thing that you mean by anti-ghosting.
Edit: I read over this thread again. I guess tall keys are a deal breaker for you. That sure does limit the number of choices. I would ignore this post and hope that some of the suggestions everyone else posts here are good
