What comes after a Trainer?
My second plane was a Great Planes Big Stik (ugly stik) if you want to call it that, with a tower hobbies .46. I have over 500 filghts on it. It came covered with the peel and stick stuff they call covering. It now has more packaging tape than anything and I like flying it as much as my 27 percent Extra 300 that has a G-62 on it. I gave a new meaning UGLY with all the tape, but it will handle any kind of wind, rain or cold you can throw at it. This plane has been thru it all and did I mention it's UGLY but flies Great!
I am a flight instructor at my field and you wouldn't belive how many new pilots that choose their 2nd plane because of its looks. Find a plane with good flying habits (light wing loading, under 22 oz per ft.) and you can't go wrong. A good way to find the right plane is to make sure you have at least 100 sq. in. of wing area for each pound the plane weighs. If it weighs 7 lbs. you want at least 700 sq. in. of wing area or more. More wing area the lighter the wing loading. I have a Laser 200 with a 72 in. wing span and 882 sq. in. of wing area. The plane only weighs 5 lbs. and comes in with a wing load of 13.06 which makes it a kite. A very gentle flying plane but it can take no abuse. I land it so slow, one could walk faster than the plane on final and never have to worry about a tip stall.
After all that, I think a G/P Big Stik, a G/P Supersportster or a
Sig Something Extra are all excellent choices. Don't rush yourself. Like Shortman said it takes time and experience to master R/C Flying. Experience only comes with time however long it may take.
Good luck in whatever you choose.