I'm not sure about a sdl porting... No one in the gbadev community uses sdl and I haven't seen any example working on fpc yet.

About fpc: there are some problems with the old memory manager hack in the 2.2.0. Long and sad story short, you could not use classes >_<.
The gba/nds port in the svn trunk uses the new fpc memory manager and it works pretty fine (supposing that you don't need recursive functions... in this case something goes wrong with the optimization flags, but I'm on it )