I won mine in a raffle (I know, I was excited) so mine's a Classical, I believe 4 or 5 qt. I really like it- when I make cookies the floor flys out of the bowl, but I've learned to live with it.
I would recommend...the professional series with the handle on the side that moves the bowl up and down. I was going to get a pro 5, but hey, I can't complain. The space between the bowl and the neck is bigger...so it's much easier to add flour and such while the mixer is going.
In answer to fragglerock1....
A hand mixer will be a work out. Once your start adding the flour, it gets thick. I would cut the batch in half for the first time- if your using the no fail recipe. I feel that getting one would be worth the money. I use mine for cakes, cookies, biscuits, just about anything I need to mix.
Good luck. Let me know if you need any help.
Steph