Interesting name - do you have a dog that you are training to sit down on command?
However, photography: I resisted digital for a long time, eventually deciding that I might as well give it a bash. Being a Nikon camera devotee since the F, and already having manual Nikkors (avoided autofocus even when I had an F4s), I settled for the D200.
It opened my eyes. It also hunched my back, as my time at the computer has gone from normal (whatever that is) to absurd.
I don't think you might need to shoot at high ratings as much as you think you do - I use the lowest rating available of 100, always RAW/NEF; the quality from these primes is quite remarkable at apertures much wider than I would previously have though to use on film, mainly because the altered perceptions of depth of field with smaller capture areas changes everything.
Yes, I was already in the Nikon system, but speaking from a practical point of view, if the results work for me, then that's all there is to it. There is so much internet chat about different marques, primes v. zooms etc. that confusion must reign supreme in the mind of anyone starting out in photography.
My advice is this: decide on a format; buy the most expensive body you can afford and a single lens at the limit of your budget. Make that lens the equivalent to a 35mm on full-frame 35mm film cameras (in the case of the D200 that means a 24mm lens). Experiment like hell and don't rush into buying lots of glass that will often end up gathering dust. I speak as a pro and I've done just that, to my shame, as has every other pro I've known!
Once you know what the single camera/lens can really do, which takes time, only then think about more equipment. Incidently, I would suggest buying new; used might be good too, but you can't know before you buy and then it's too late. A poor camera/lens can seriously impair your learning and, importantly, expectations.
Ciao - Rob C