With all due respect, you have not done nearly enough research to start mining. You need to ask yourself whether you know enough about bitcoin to actually mine your way to profitability (i.e. research "difficulty"). Have you looked at trading, the price volatility and a lot of historical data to determine for yourself whether you will ever recover your investment little enough make a profit?
It is clear that you have not done much research because the answers to all your questions are easily found in these forums. Don't jump into the ring until you know exactly what you are up against. You can do the research diligently in a short amount of time (referring to everything that I have mentioned).
I hope you take this response seriously and make a sane and logical choice and not an emotional one (driven by excitement and lust for easy money).
I think I have done enough research considering bitcoins itself, trade value and EVEN difficulty, yeah!, that is not what I asked for. All I want to know is how to get my rig up and running, it's just a hardware issue. Sure, I can just buy all that stuff that I already put together in some webshops, but I tend to ask for advise before encountering problems which could have been avoided with just a little question at someone who is already in this business. We're talking about 2000 here, I'm not a guy who spends such amounts of money hoping everthing will turn out just fine.
I searched this forum for hours regarding the VGA dummys, but all I came up with were people already knowing everything about these things and discussing what is best for overclocking etc.