Alex,
The Sc1435 supports the 2200 and 2300 Opterons. The fastest one we have is the 3.1/2.2GHz AMD Opteron Dual Socket 2379 processor, part number C350R. As well as the 2.8/2.2GHz AMD Opteron Dual Socket 2387, part number T935N.
Let me know if this helps.