Totem Speakers and Home Theater

I have 4 Totem Mite bookshelves speakers (FR, FL, SR, SL) and two Totem Mite-T center channels, one in the front and one in the back (TWSS). Here is my question... Do I get a pre-amp and an amp as individual pieces, or just a single integrated receiver? What are the pro's and cons. I certainly have the room, but I would rather channel my entire budget into one unit - it seems most practical, but I am very open to suggestions from pros! My max budget is $1000. Please help. Thx.