Can't help you with SA, but I can tell you is easy to do yourself.
Here's my learned-the-hard-way top tips:
1. measure and mix it correctly
2. degrease and degrease again
3. let it dry a WEEK before touching it (bake it the oven for about 30 minutes at lowest setting)
4. do a second coat after a week and don't even TOUCH it for another week