Barry,
Having recently been to Florida to do some flying training and hearing all the horror stories about students coming over to fly with certain schools, after being told not to bring a Visa, I would highly recommend getting an M-1 Visa to do your flying training. Naples Air Center have written a very good post on exactly what is needed when going to Florida to train or just to fly. I would highly recommend reading it, you will find all the information there. Personally, if a school in Florida told me I did not need a Visa to train over in America - even after all the recent events - then I would not touch them with a very very long pole!
I spoke to someone who signed up for a PPL course at a particular FTO in Florida, who advised him he did not need a Visa. He was subsequently turned away at immigration.
Besides think about it - the cost of an M-1 Visa or the cost of losing all the money you have invested in the "getting over there" and not to mention the cost of the disappointment you would face at the airport when immmigaration turn you away. Just make sure you leave plenty of time to get the visa as I know the US embassy are being particularly cautious at the moment and taking a wee bit longer than they probably should.
Oh and just one final point - Hi Gonewest. How's the crabshack?
Many regards and hope this helps,
Rossco