RE: What a good plane to get introduced to high speed?
If you're comfortable w/ low wing planes already, why don't you go ahead and get the XL? It's only fast if you have a strong engine and push the left stick all the way forward. Tower has the kit and the Tower .75 for under $200, Put an inexpensive set of retracts in it and it'll be a nice step up for you. Later, after you're comfortable with the speed of the .75, stick a Jett 91 in it and hang on!!
tim