Honestly if you decide against the wii want a High Def system and are that tight on money i'd just go with the 360. It's a bit cheaper so you can get some games earlier plus it has more good games out now.
No Blu-ray but really is having a Blu-Ray Player + Game player really going to matter in your case? If you could only afford a game every other month you probably don't have much money for movies right? Blu-Ray movies cost about the same price as a game.