Chuck' s suggestions are good ones... But, if you want to spend all $900 I would go with a Sig Kadet LT40 ARF, OS .52 4 stroke and a Futaba 9CAP radio system. This would be about the best trainer system money can buy and with that setup you will be happy with it and bring it to the field often forever.... Its a VERY kick butt knock around plane and is one of the most popular trainers EVER. Its a ball with an OS .52 4 stroke, and no it is not too much engine. The radio would seriously be the last one you will ever need, PERIOD. It will support about 16 or so models. I cant remember exactly how many but its a bunch. Dont let anyone scare you away from the 4 stroke,,, its no more difficult to use than a 2 stroke, gives you more power and torque and is just an all around great engine.. If you want a really seriously awsome engine in there, go with a YS .63 and buy a less expensive radio like the Futaba 6EXA. You will come out about the same.. I still think my original suggestion would make you more than happy....

LT40 http://www2.towerhobbies.com/cgi-bin...&I=LXFG19&P=ML $131
OS .52 4 stroke engine http://www2.towerhobbies.com/cgi-bin...&I=LXBY59&P=ML $189
Futaba 9CAP Transmitter/Receiver http://www2.towerhobbies.com/cgi-bin...=LXHMD2**&P=ML $389
Futaba s3010 x4 Servos http://www2.towerhobbies.com/cgi-bin...&I=LXDTB3&P=ML $100

$800! and a kick butt setup. Plus you have $100 left over for fuel, glow plug heater, starter, battery, ,,, whatever.