We will occasionally be at sector67, check the previous messages for an idea of when.
As far as equipment, you must work with an intel based Mac. Which means anything you by new. If buying used and it has anything like G5/G4/G3 in the name or on the case, it won't work. You could get in cheap with a Mac Mini for around $699 new, but I recommend going to the MacBook Pro 13" if you can. Little more horsepower + portable is a win in my books.
If you do embedded C, then you might be able to migrate to Obj-C without too much trouble. It is based on C and uses a lot of C coming out of the NeXT SmallTalk code.
Greg