[CentOS] Opteron in 32-bit mode

I'm spec-ing a development server for some Haskell hackers. In particular, they need to be able to build and run the Glasgow Haskell Compiler (ghc), the x86_64 port of which isn't quite there yet.

My current thought is to get an Opteron-based system, but load it (initially, at least) with the 32-bit i386 version of CentOS. That buys me near-term ghc compatibility. In the future, should ghc become 64-bit clean, I'll be able to upgrade to a full 64-bit OS.

The alternative is to build the server around high-end ia32 chips and leave the Opteron for another day.

Does anyone have experience running a 32-bit-only OS on Opterons? Are there any gotchas?