Beechcraft King Air diverted to a suitable airport and landed safely after suffering a catastrophic engine failure.

Narrative

While enroute at 17;000 FT; the right engine on BE90 failed. After approximately 3 minutes of determining the cause of failure and if the engine could be restarted; it was determined that we experienced a catastrophic engine failure and it was shut down and feathered. We advised Center of the situation and told them we were going to divert to the nearest airport; which was ZZZ1. Center instructed us to maintain 17;000 FT; however; we could not maintain altitude. They later advised 'altitude at your discretion.' Beginning a slow descent to 12;000 FT; I was able to maintain that altitude with the right engine feathered; and was able to maintain an IAS of approximately 150 KIAS. Due to the relatively good performance of the aircraft at this point; we elected to proceed instead for ZZZ Airport because they had better facilities to assist us. ZZZ is approximately 50 miles north of ZZZ1. ZZZ2 was 1/2 way between in the event we could not make ZZZ. We arrived over ZZZ at 8;000 FT; made a wide circle around the airport while communicating on UNICOM in order to make sure all traffic in the area was aware of our situation prior to us landing. The landing was made successfully and without incident. We did not declare an emergency.