RE: What a good plane to get introduced to high speed?
samolot,
I can understand the "comfortable" factor of a new plane. Another possiblity you might want to look at is the Sig Kouger. It's relatively inexpensive (~$75 I think), uses a 25-35 size engine (again inexpensive), has jet-like looks, is fast but not crazy fast, and lands very nicely if built light. The Sonic is a good choice too, but this might be a good compromise for you, giving jet looks and fairly gently handling too. If you want to go fast down the road you can stick an OS 32SX in it, or go with a Jett.
Hope this helps! Of course, neither the Koug nor the XL are ARFs - you're going to have to build them.
tim