So the SF position is very limited to what i see so is there anyone that has teams that doesn't even carry a SF position?
If so what would be the best replacement?
A SG, PF, C?
Any ideas on this.

I've used both SG and PF at that position. The SG needs to be a decent rebounder. The PF needs to be a decent PER shooter

I've gone 3 guards- none good at rebounding before.  the other 2 were pretty stout rebounders (99) and it worked ok.  Probably won't win a championship that way though.     

Have used a SG there before with some success.  Especially if both SG are worthy of starting.  I had 2 SG drafted one year at 2 and 4 (My only draft picks FYI)  SF is always a difficult position unless you have access to the elite.  There are players at other positions that have SF type numbers though and that is what you want to look for. not what position they have, especially now that the position penalties have been eliminated.

SF seem to be better in D2 and DI. I recruit them in D2, did not in D3.

I have won title with sg's with low rebounding so anything can work