A higher end Kimber is not a better made gun. It just has more "features" off the assembly line. Since an entry level Kimber is just as likely to have a decent trigger pull, has as visible sights, and no more sharp edges than the high priced spread, (Cooper's critera.) it is at no disadvantage except cosmetically. The only thing you might reasonably add that will really help is a mag well funnel.
You do not need an ambi safety in IDPA (Unless you are lefthanded.) Strings shot with the gun already in the weak hand require only that the finger be out of the trigger guard, there is no requirement that the safety be on. Extended slide stops are prone to inadvertent engagement and I have taken them off a couple of guns.
A Glock does not make a good paperweight if you cannot adapt to it quickly; it is not as heavy as a 1911 you don't like.
Hard to argue with the cost of ammo, though. There is nothing cheaper than 9mm econo-ball. A 9mm 1911 is a smooth shooting gun, too.
I shoot a 1911 .45 CDP better than any other gun. I don't mean only that I carry a higher classification, I mean my raw scores are better than with even a very similar ESP. (Unless there are some maxed out 18 shot scenarios that cost a reload.) I don't know why, that is just how I shoot.
You have to start somewhere and we can't tell you what you will do the best with. Just as well go with your heart. If it doesn't work, well, gun trading can be fun, too.