RCKen's "Looking for a trainer?" thread http://www.rcuniverse.com/forum/m_4537845/tm.htm has a huge listing of second planes that would be ideal for moving up.

Everyone has their favorite, so I will not make a specific recommendation. Follow the links and pick the one YOU like best.

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That Extra will cost $1000 minimum to be ready to go, and it would be easy to spend over $1500 if you go with high end digital servos. I'd be afraid to fly it with that much invested. My models usually have $500 or less streaking through the air.
I based the cost estimate on using the OS 1.60FX. The Super Tigre 3250 is about 2 cubic inches and costs less than the OS. I know people who have the big OS and they like it. I do not know anyone who has the big Tigre.