Layne,
My opinion is to start out with Basic.
I know the maneuvers seem easy to and very "basic" but you'll be suprised at how hard it is to fly them in sequence and do it well.
Wind correcting each figure is something you may or may not do now but you will be forced to in IMAC.
Flying and being judged is also a nerve wracking experience. You can practice the sequence a million times but the first time in front of judges you wont even know your name let alone what the first maneuver is.
Another reason to start in Basic is that each class builds on the previous class. You really are going to be pressing yourself by skipping through the classes.
If you fly your first contest in basic and have no trouble and win every round then I'd move up to Sportsman.
Then welcome to the world of the Unknowns. (Basic does not fly Unknowns)
They hand you a sequence Saturday night and the first time you fly it will be Sunday morning infront of judges. Fun but difficult.
A bunch of us got into IMAC last year and have an absolute blast.
I'd much rather fly a good sequence now than do an inverted harrier on the deck.
Dont get me wrong, I love 3D but its easy to hide sloppy flying in 3D. You cant do that in IMAC.
Precision flying has also made my 3D better.
Have you checked out
www.mini-iac.com ?
All the info you need is right there along with the 2005 sequences.
You can still get your fix for 3D by doing the Freestyle competitions at most IMAC meets.
Have fun!