This right here is one of the best shooting 9mms I've ever held, and this is coming form an HK guy. Very smooth shooting and accurate. Has/had a drop in Jarvis threaded barrel. Older UU prefix Sig P226
The black ones make better conversion candidates. I wanna say my UMP conversion was around $4000 total. If you can't find a black one, there are tutorials to dry the grey black, but I wouldn't.
You never actually stated a budget so this would be my true #1 pick. If your budget allows.
https://www.budsgunshop.com/catalog/mobile/product/719015905/anschutz_1416d_hb_g_22lr
I'm right handed but left eye dominant. I shoot all of my rifles left handed. It's an easier transition than you think. In fact, it's downright difficult to shoot a rifle right handed anymore.
I get so many bulk emails anymore Midway doesn't bother me. I recently picked up some decently priced 10/22 mags. I still check them when I'm shopping for parts but rarely are they cheaper than anyone else. Shipping seems to have gone down too.
I used to do this as well. You can also go to Home Depot/ Lowes and get a clevis pin for under $2 and it works wonderfully as well.
Slide in clevis pin through the "ears" that hold the pivot pin
drop in spring and detent
push down with punch
rotate clevis pin to act as slave pin
push clevis...
You listed it as a practice rifle, are you wanting something that simulates centerfire type shooting? Are you married to the 17 caliber? Will you be shooting at varying distances of targets or mostly 100 or 200 yards?