Hello,
While it is a good idea to get a MacBook if it suites you needs we really can answer which one you should get. We can give you the info you want but you have to decide which one is right for the tasks at which you wish to accomplish. Will the $1100 one do what you want? If so then get that. Do you think you will need the extras that the $1500 one offers? Then get that. It all depends on your needs.
The main differences i see is that hte 2nd tier MacBook Pro has 50GB more Hard Drive space and a more powerful video card. If you want that go for it. Worthy investment. But make sure you can run what you want on it.
Cheers,
Mak