If you don't want to spend alot now, here is what I would do. Decide on what (main) speakers you like the best. Then, buy your rears in the same line for now. Use as mains to get you by. Next, get the matching center. Then, move the mains to the rear when you are ready to buy the most important part. The mains you liked in the beginning. This way you will not be throwing away money on speakers you will not need.