The Opus might be fast, but no need for full power going stright down if you don't feel comfortable with it. F5B gliders do fly very well and very clean, start and lands very nice... but the fuselage are very tight and will just shoe horn in the parts needed.

On this kind of small model the distance between exhaust and vertical stab is short, might be a problem on a conventional stab/fin setup. (anyone messured the temp 0.5-0.7m behind the turbine?!)

One option might be the 2.4m Salto from Baudis (the guys making the Banana slope racer) http://www.icare-rc.com/salto_h101_2_5m.htm. small enough for good performance, yet capable of taking fuel for more then 2min of full power :-)