Some very good advice here. Looks like you're on the right track. The Extra 300 has always been one of my favorites. This past fall I got one from Horizon that has turned out to be one of the planes I take to the field nearly every weekend.
http://www.horizonhobby.com/products...f-blue-SEA2500
This plane is very reasonably priced and put together well. Mine has a Tower Hobbies .75 and flys great. I would suggest an OS 75AX with a Bisson Pits muffler.