Any plane from Wildhare, Aeroworks,or 3D Hobby Shop will work great for you. I like the Wildhares myself. I would stay with the better known dealers. I've seen some of the cheaper companys planes that sounded like a great deal but were total diesasters.
The DLE 55 seems to be a good engine. Quite a few at my field and everyone seems quite happy with them. I have their 100 and it runs great.
As far as servos I would buy the best you can afford. Make sure they are metal geared.
For batteries I prefer the A123's for the reciever and for the ignition a good ol 4.8 nicad will serve the purpose very well.
On a 50cc plane one 2300 A123 going into a Smart Fly super switch with two leads going to the reciever will be plenty.