If the hammer is down, the three things you can control about how much force is required to rack the slide will be: (1) mainspring, (2) firing pin stop, and (3) recoil spring.
A lighter mainspring will make the gun easier to rack. I've had a couple of .22 1911s done for myself, and went with 17# mainsprings.
A lower, smaller radius firing pin stop makes the gun harder to rack, but most 1911s you'll encounter should have the higher, larger radius firing pin stop.
You can get "calibration packs" of recoil springs that'll let you try out a variety of springs. "Heavy" springs run 18-20 pounds, 16 pounds is a typical factory .45, and you can get springs down in the 10 pound range.
If you're shopping for new, I'd encourage look at a Dan Wesson, Colt, or Springfield in 9mm. They should all have the higher, larger radius firing pin stop, and you can play around with the springs. Honestly, though, I'd spring the gun for maximum reliability and best tracking, and deal with racking the gun by learning optimal technique and improving hand strength.
We have some very knowledagble 1911 users in the forum, and I'd encourage you to seek them out.