You will find with the drafts that they don't have the endurance of a light horse. They are built for explosive power, and slow and steady work. If you want a horse you can canter for miles, a draft is not for you. My perch can literally leap from a stand still into a full gallop without a blink of an eye, but he can't canter for over a mile without tiring out.
Also with drafts- they are very prone to EPSM (monday morning disease) so PLEASE do some research on diet. They need to have a low sugar, high fat/high fiber diet. Sweet feed is a huge no no, nothing with molasses or refined sugar. I use a complete senior feed for my horses.