Try the Jett BSE 30 or 35

Worth every penny, and both out perform most .40 and .46 engines

The BSE 30 AAC engine weighs about .70oz more than an OS 32, but it will turn a 9x6 APC well over 18K rpm.

Very user friendly.... has a usable RPM range from about 16,500 up to about 20,000

Short of that, I'd second the vote for the Webra. Nice engine. Put a Jett-stream muffler on it and it will really sing.

Bob