I have not seen draft Stout at all on the island.
Places that do the regular on draft include:
El Divino, Banana Beach Resort
Catamaran Bar, Caribbean Villas
17.55 (Formerly 'The Playa Lounge')
Pier Lounge (I think)
Bar at Pelican Reef Resort
The Sports Bar
Guess who is a draft drinker ?
I am sure there will be some others. To me, best draft is at El Divino, chilled fresh glass every time, and rapid turnover as they do not see bottled beer. They do Lighthouse too, for those of you with that peculiar taste bud!!!