If you are going to do most of your cave diving in Florida, do your class there. Handling the depth and flow and the different rock type is quite different from what you do in Mexico. I did my original cave class in MX and my first cave diving TRIP to Florida, and it was a rude shock!
Lodging in MX isn't that bad, if you can share a place. We're renting a 2 bdrm condo right on the marina, near the beach, with a ginormous, gorgeous swimming pool. The place has its own laundry facilities (something which is AWFULLY nice for divers) and is within a 2 minute walk of all the restaurants in PA. The cost will be $240 a week per person, with five of us. Now, if you rent a cottage at Dive Outpost and share it with three or four people, it will be cheaper, but much more modest. Motel rooms in High Springs will run you the same or more, and will not have kitchens or laundry facilities.
Car rental in MX is brutal, if you buy all the insurances. Your American Express card will cover the liability insurance, but you'll have to have enough room on the card to set aside the cost of the car to avoid the collision insurance.
Food's pretty cheap in either place, but I'd rather eat cheap Mexican food than cheap American food. That's just me. Floyd's has GREAT food.
I think tank rental runs about the same in both places.
Our cave 1 was five days, and they were five REALLY LONG days. It would have been nicer to have done it in six or seven, but I think that's hard for the guys to schedule. We started at 7:30 a.m., and a couple of nights, we got back to the condo around 9 pm. Luckily, we had my husband to cook for us!
I have never dived with Chris, but I did Cave 1 with Danny, and did Cave 1 redux (diving as a buddy with a friend who was doing a reeval) with Fred. They are both excellent instructors. I'd have no problems taking Cave 2 from either of them (yes, I realize Fred doesn't teach Cave 2 yet). They do have different personalities, though!
Overall, having dived in Florida and dived in MX, I prefer MX, because you get much more bottom time with the low flow and the shallow depths. I think the caves in both places are beautiful, although they are different. I also think it's a great idea to get some experience in both places.