I second Daves nomination. I test flew a wing mfg AT-6 with the Jett .46 on it last spring, and it flew VERY well
I have a kit sitting in line near my workbench too. Nice kit. Builts like a typical foam/wood Q-500 airplane.
The HOB P-51 is a good choice too......keep it light.
Also....... look around for some of the older F-1 and QM-40 and QM-15 kits. Older Prather Toni kit, Stafford Ricky-Rat, Matney/Latsha Rivits. Sig use to make a Mustang 450 kit ... a F-1 design from back in the 1970s - flew nice. They have great lines, and make very nice sport-speed planes for an experienced pilots. Sometimes you will run across these at swap meets and such... and occationally you can find built, used airframes that are not all that difficult to convert to sport use. Matneymodels still has kits for the QM15 planes. His QM40 planes are quick, and fairly current designs.
Other options.......
Great Planes .40 size P-51. Lots can be done to make it a little lighter, and it can be modified into any one of the number of Reno P-51 aircraft. It basically has a Kaos .40 wing, which is a bit thick, but with the gear up and the plane cleaned up, it will move fairly well.