Hope I'm not too late to recommend these braces:
http://uk.damonbraces.com
They're AMAZING!! Still train tracks but work much quicker than normal ones. I only had my bottom teeth done. Had one tooth practically behind the other and I only needed them on 3-4 months!!
I had braces when I was 14. As I was young, I didn't really bother keeping up with the retainer. Luckily my top teeth stayed perfect, but my bottom teeth moved back. Lesson learnt hard way.
So I did pay for my bottom braces years later. I now have a permanent retainer glued to the back of my teeth. I'm too paranoid to have it removed, and so used to it now it doesn't bother me in the slightest.
I highly recommend trying to have a consultation with someone who does the Damon.
I don't remember any lisping. Maybe for the first week or two, but fine after that. The braces can feel sore, or dig in after they're tightened each time. It's good to buy the balls of wax you use as ear plugs. It's good to rip a little ball off and pop it over any area that's rubbing.
Good luck hun, it's all worth it xx