I read '24 in competition' as "24 inch competition" and thought whoaaa, that's a glock!
As was said, I agree with Dawson's too. Easy on/off, and some of them come with the +power mag springs..
Shoot it first before you worry about major upgrades.
As far as springs, develop a good load for it first, then look at the recoil spring, but +power trigger spring and minus power striker spring/lightened striker and plunger spring are usually cheap enough to do now.
Look at the minus connector, and look up on here or the youtube about the $0.25 trigger job on a glock.
Mag drop comes down to preference, I've never tried but I think the "paddle" style ones would be fun to try: http://www.brownells.com/handgun-parts/frame-parts/magazine-release-parts/magazine-releases/standard-mag-release-for-glock-sku452000001-7580-18856.aspx?ttver=2&utm_medium=shoppingengine&utm_source=shopping&mc_id=17000&gdftrk=gdfV21820_a_7c187_a_7c1021_a_7c452000001_d_452000001_d_10729
I also think that, for much as you'll be taking the slide on and off, these are invaluable: http://www.brownells.com/handgun-parts/frame-parts/slide-catch-parts/slide-catches/extended-slide-lock-lever-for-glock--prod22920.aspx?ttver=2