Good to hear folks taking a course BEFORE they buy a gun.....I'm an NRA Instructor and I wish everyone would do that!
As far as finishes....pretty much any quality finish, even parkerizing, is better than standard blued finishes. Matte stainless, Robar's NP3, Birdsong's BlackT, hard chrome, and Glock's factory finish are all excellent. Your individual use will determine the finish best suited for you. Beretta's proprietary Bruniton finish is ok but I've owned Beretta's that had the stuff flaking off after only a coupla months.
I recommend a Glock across the board for new shooters who want a semi-auto pistol. That finish is as close to indestructible as the industry offers in my opinion....and the gun ain't bad either.