Dave,
I bought my first jet almost a year ago now. It was an SM f-18C in a blue angels color scheme. I loved that thing. I loved it so much I had to sell it.
Remember what people are saying here. There is a huuuugggeee psych component to flying these things. You will be nervous your first few times. Learning about sink rates AND turbine lag are difficult.
Darcy (mu2driver) is a GREAT flyer and flew the living crap out of his 18. Really a site to be seen, but ask him if he respects turbine lag.
18's are great with a very predictable sink rate. But they have a very real sink rate. Prop planes don't really have this phenomenon.
I'd suggest to learn about turbine lag first THEN about sink rates. This makes a minimum of two airplanes. Buy some sport "junk-a-lunka" to learn turbine lag on, (Rookie, A-10x, boomerang). Put fifty flights on it. You will get behind the turbine a few times and rip the gear out or hurt the fuse/wing. You will learn it on an airplane that is cheap and you won't care so much about. Think of it as an investment in yourself. Buy a P-120 and put it in the big boomer and use the engine in your f-18. Try not to care too much about the looks of the boomer (yeah its ugly, but so are most sport planes
) you are going to get rid of it anyways.
You will use this skill to help you keep your next scale bird, that beautiful f-18 (believe me I love that airplane, I own 2), from falling out of the sky on approach. It will not let you get away with getting behind the turbine as much as the sport junk-a-lunka.
What ever you do, don't do it alone! You'll love it though!!!!
Raf