Hello all! I'm new to this forum, and bonsai in general. I bought a Ficus Retusa last year, and have enjoyed it greatly. My wife thinks I'm obsessed with it. I've even named it!

I'm looking forward to learning a lot from the experts here.
I have a question about growing a new tree. What species should I try? Maybe a little background will help. I live in Oklahoma, and the climate is varies greatly here. In the summers, the temperature can reach 100 to 105 degrees often. In the winters, the temperature will fall to the single digits and teens. I have kept my Ficus inside (at around 68-74 degrees) since around October, and it seems to be doing quite well.
I'm looking for a tree that can handle the extreme heat that we get here in the summer, and also will survive the 4 to 5 months that it will have to spend inside every year. Pretty much the only light that it will get inside is a special plant light-bulb, but I don't know how much that actually helps.
I tried what's known as a "mimosa" tree around here earlier in the fall, but it was not working. I don't know what the exact name of it is, but it's an extremely fast-growing tree with fan-like leaves. I will probably try another seed in the spring.
I know that most conifers will fit the bill, but I would prefer a deciduous tree if at all possible. Fast growing is preferred as well. Also, I would like one that changes at different times in the year. Maybe the leaves change colors and fall off in the fall, or it blooms flowers in the spring, or it might grow fruit...who knows? Any suggestions?
P.S. - I want to post a picture of my tree, but I don't have a digital camera.
