That's pretty much my game anyway but it seems that you have to enter the money with a nice big stack. What's been happening to me is that even though I get into the money, I'm usually so short stacked that I'm done pretty soon there after.
Another hardship is keeping my focus and concentration going for that many hours in a row. As you know, in NL one false move and you're down half your stack or worse. So I need to work on my concentration for the longer term.
But the MTTs are much more exciting than the S&Gs so I'll keep pecking away at them while continueing (hopefully) to build my bank roll in the S&Gs.
Poker stars has a great Sit and Go of 180 players for a $20. buy in with first prize of $1000. They last about 4 hours and that's what I'm shooting for in the near future.