I'd have to agree with mnrcaerobat, an extra is not a good second plane. I'm flying a sukhoi currently and it's my 7th.

Good choices would be the four star 60, ultra stick, super sporter, tiger 60, venture 60. Even the stinger 60 ARF on low rates would be ok. They are all great planes and excellent flyers. Extras, caps, edges and sukhois can snap at slow speeds and have much higher flying and landing speeds than any of those above.

If you really must get the extra, get some experienced help for the first few flights. Have a fellow club member take off and land while you get some stick time up there, get a feel for the much faster plane. They can really get ahead of you quickly. Good Luck.