This is a little long so thanks for even reading it!

I am an audio enthusiast from Wisconsin. I am currently in college and am limited in cash flow, but my one indulgence is audio systems. I live in a dorm that is 10'x15' and I currently have a system in my room, but it is pretty low end and I am looking to upgrade part by part. I currently have Sony SSMF515H towers for the fronts, which are not great but I got a great deal and I needed somethign for the time being while I was looking for better speakers so I bought them. I am very disappointed with them and I an looking for new speakers. I have been looking at definitive and bostons and NHT primarily, but though they are great speakers, defs and NHT are out of my price range, and boston I have heard are quite inefficient for the price, and I happend to hear about axioms, recently when I bought a sub. I recently acquired a Dahlquist PDQ1200 sub and am quite pleased with it. Enough with the rambling though, getting back to tthe point I need some advice on your speakers, which I want to give a try. My room is currently and will probably be for the next few years 10'x15', but I want towers and I need some advice abouut them.
My current system:

Sony STRDE575 receiver (will be upgraded within the next few months to either a rotel, denon or pioneer elite (could use some advice on that too, based on the speakers you recommend))
Klipsch Quintet rears
Sony SSMF515H towers
Dahlquist PDQ1200 sub and
crappy Jensen center (definitely has to go)

So I need advice on picking between the M50s and M60s an would like to know what advantages I would get. and also a center that is not too expensive but goes well with the speakers you recommend, I'm guessing either the VP50 or VP100. I would also like some advice about the receiver you would recommend with that, whether the inegrated would be the best way to go for me or if I would really benefit from and extra pre-amp, etc. Since this is the one indulgence I let myself have, I am ready to spend some money, but I would also like to keep it reasonable, no set budget, but reasonable, you know how it is to be a college student.

Thank you