When you talk about 'draft' horse, are you speaking specifically about a heavy horse like a Begian, Clydesdale, Percheron or are you talking about a good all rounder heavier type of riding horse. In the UK we call the latter 'Cobs'. If you want a cob, then it really is down to temperament and how he/she feels and looks. If, like me, you adore Heavy Horses then that is what you should get for yourself. I got my first 'Heavy' (a Clydesdale) when I was 49 and he was 4. I got my 2nd Clydesdale when he was 15 months and I was old enough to know better than to get a 2nd heavy! (LOL) I have not one regret. There is no specific breed in a heavy which makes one type better for riding than another. Go see a few heavy horses which have been broken for riding. Then you go for the one which you like best and meets your needs. If you are worried about getting on and off, costs of feed, price of tack (much higher because its harder to get the right size), negative comments from some people who ride ordinary horses etc. then perhaps a heavy is not the right horse for you. However, if you have thick skin, a step ladder to mount from, want a giant puppy dog following you around everywhere, want to feel like you could look into heaven when you sit on a horse, want to feel 1 ton of love evertime you have a carrot in your hand then you go get yourself a heavy!