S-33 is just fine for a Belgian tripel. Noble hops are also generally the flavor you'll be looking for. I make mine with Tettnanger and Hallertau usually. Fermentation can be on the warm side for most Belgians with no problems. I brew my tripel at 62 degrees and it turns out fine. A good solid three week fermentation with a month of bottle conditioning at a minimum will dry it out and eliminate any acetylaldehyde (green apple) flavors. To be honest, a Tripel with some Acetylaledhyde is frigging delicious but it isn't to style. They should be dry with just a hint of malt sweetness.
No need to raise the temperature on it. Just let it sit a good three weeks minimum on the yeast cake and a month isn't out of the question. Make very sure that the beer has fermented out below 1.020 to avoid risk of a bottle bomb and prime with 3/4 cup of dextrose (corn sugar) per 5 gallons. Adding a teaspoon of yeast nutrient AND yeast energizer each would be a great idea. Add them in at 10 minutes left in the boil. After pitching and sealing into the fermenter, shake the hell out of it and get as much oxygen into the solution as you can. Just tilt the fermenter bucket/carboy on it's edge and rock it back and forth gently to make the wort slosh around in there for about five minutes time. This will get plenty of oxygen into the wort.