If this is your first time using a wet saw, you may want to look at renting one if your tiles are 13" (most likely 12") and you plan on doing diagonal cuts. For straight cuts the TM-75 will work like a champ, but cutting the diagonals will require a bit of freehand work since the table isn't large enough.
The one thing thing that sold me on buying a saw was resale value. When you calculate out the number of days you plan to rent a wet saw in relation to having the convenience of having it by your side to fix a tile you may have screwed up the measurement on, it usually balances out.
If you're doing more than one room, I would definitely recommend buying the saw and selling it later. I bought a Felker TM-75 for the exact same purpose but for smaller tiles and I have say I've saved my money in headaches.
I'd listen to John, he has a great review of sawa that may fit what you need. From what I hear, if you get an MK, also get a set of earplugs.