I'm doing the exact same thing. As of tomorrow, I'll be running four 6770's at 240kHash/s each mining litecoin. Right now just two. I've been building my next rig in my head ever since I got my first one built. I'm hoping these ASICs ship soon cause its going to be a free for all in the hardware section of the forum. Will be a great time to pick up gear for next to nothing.
I decided to put solid processors (AMD FX series), at least 8gigs of ram and a stable video card, that runs cool, in my rig. The parts are built buy the same manufacturer (Gigabyte, had some great experiences with their server boards). Its simply a matter of building durable rigs that I can throw at whatever needs mining. Cost an extra $200, but like you, I'm in this for the long haul. What I'm not spending on electricity (its included in the rent) and isn't being spent on maintaining an office (eff that noise) is going directly into rigs.
As for sticking to one crytocurrency or another, I'm undecided. You know how it goes. When your favorite sports team starts to loose there are a million reasons why there losing. That doesn't work so well when dealing with investors. I've found its best not to be biased in these matters.
Nice, sounds like a good rig

I kind of want to mine a little bit before the ASIC's get here, because then I can get a nice supply of LTC before the difficulty goes through the roof.
I'm pretty much putting all my money into this at the moment. Gonna get as many rigs as possible and just let them rake in the coins.
Yeah I know what you mean. However I think Litecoin's gonna be a good one to stick with
