Hossfly's advice is sage. Your second plane will be the plane that you will be learning to perform acrobatics with and pressing the envelope with regard to speed and whatnot. As such, second planes have rather short life expectancies.

A World Models Sky Raider Mach II, Super Sport 40, or LA Racer 40 ARF would be a wonderful and inexpensive sport plane with which to learn Cuban Eights, Immelmans, Split S, outside loops, wing overs, and a whole host of other stunts and manuevers. These planes can be well-powered by inexpensive engines and you could outfit a whole airplane including flight pack, airframe, and engine for about the cost of a Saito .82 engine.

It's nice to have an inexpensive sport flyer like this in your hangar in any event. Days will occur when you want to fly but crosswinds or 25 mph gusts will have you thinking twice about taking your pride and joy out to the flying field. A Sky Raider Mach II with a Magnum XLS .46A and Hitec flight pack in it is a great cure for this problem.

Check out the airframes at http://www.airborne-models.com before you make a final decision. You can always take your time and put that Pulse XT .60 together and fly it after you've gotten a chance to abuse your Sky Raider Mach II for a little while.

Good luck and good shopping