I see you've tried blacks and browns. Ever tried Topre? I ask not because you must spend the $400 you have, but $400 does give you budget for a Realforce 87U if that's your thing. The catch is that it may not be your thing. On top of that, there's choices to be made - silent, normal, variable, 45g, 55g.
I suppose it would be ideal to see if you could find a Realforce, ANY Realforce, in buy and sell and give it a try. Then you'll have an idea if the feel is for you and go out and get your "dream board". You will spend less out of pocket this way and still discover whether you like them or not.
Personally, I found that although I loved the feel of the 55g Realforce switches in theory, they did not work out for me in the long term. My speed suffered and there was a certain degree of fatigue. I've since picked up a variable 86U which I've been using for just over a week and this works much better for me in a work environment (no gaming whatsoever). I also have a couple of MX brown boards, a Model M and a compact board with some kind of ALPs switch. I always use MX browns at home, and I'm in the process of moving from the Model M to either the 86U or another MX Brown board. I'm giving the Realforce a good test drive in order to form my opinion. The touch is very, very different between MX browns and Realforce.
Don't feel the need to spend $400 just because you have $400. I'm not sure why you'd prefer to use PS2. USB is nice and clean, supports at least 6KRO on most good boards, allows you to use hubs, boards like the Leopold have detachable cables so you can order a cable of exactly the right length for your installation from somewhere like Monoprice, USB is hot pluggable etc...etc... I think there's hype in some less-informed forums about the superiority of PS2. It's true that you can get true NKRO but I haven't really had a problem with 6KRO - maybe you would, I don't know.
