Hey IF... the 17Rem is King in commercial 17's, but the real 17 Kings are the 17 DT, 17 Classic and 17 Athena wildcats. Of them only the 17 Classic can be used in the Contender though.
I don't understand why component availability would be any different between the 17 Hornet and 17 Fireball? Brass for either should be plentiful, and there is plenty of 22 Hornet and 221 FB brass around to form your own.
Regardless, if you go with the 17H you will greatly enjoy it. Years ago (before the 17 rimfires) some of us old wildcatters used to say the 17AH was the most fun you could have with your clothes on. The 17AH was a PITA to prep and load for in large quantities like I did, usually 1000 at a time until I had around 10K formed cases. But it held up very well since I didn't push it too hard with my loads. If you reload the 17H just keep in mind that in the small case it doesn't take much powder to spike into the unsafe zone. 1/10 of a grain can do it when you get close to max, and neither the Remy or Winnie brass is very strong. Ambient air temp swings can also be an unsafe situation with near max loads, leaving ammo in the sun even worse, so I had summer and winter loads - and in the summer kept the ammo in coolers when out hunting. Maybe overkill, but when you live on a desert the smart move. Lots of folks swear by Lil'Gun or N120 as the powders of choice in the 17AH, I mostly used MilSup680 in all of mine the latter years when the volume of shooting was so high, 4227 or H110 before that. Had a couple of jugs of Lil'Gun and one of N120 bought just for the 17AH's, but never used any of it. Those powders would all work just as well in the 17H. While I did shoot some lighter bullets in my 17AH's sometimes (custom 18's/commercial20's), my decided choice for all my hunting loads were based on the commercial and custom 25's, and custom 24's for all my 17's from the 17 Squirrel up, with the lighter bullets standard only in a custom 17CCM.
FWIW