1. The reason why people practice with 5/30 mags is to get as real feel as possible to the potential SHTF situation Some people travel to normal States for competitive tactical shooting, where 30/30 or 35/35 etc are readily available, so training w/ full banana mag is definitely a good idea for competitors/ SHTF
2. Using stripper clips is definitely faster than loading a mag, after you run off mags... before that moment: mags is the way to go
3. XCR mags is a bit strange mod as it is just 10 rounds and the mechanics of it is of AR15, but the overall rifle feeling is SKS-so this may be a brutal physical exercise + tactical shooting combo, not sure though it would help for competitions or real life SHTF preparedness in what concerns mag availability, but it will help moving on the field, transitions etc 'coz you have 10 rounds before next mag change or secondary weapon use.. so still helpful
4. So, unless you really really in love with SKS, which is one of the best platforms available for Canadians and or u would like to get AK-like tactical exercise practice... AR w/ LARs is the way to go... even though AR mechanics is much less reliable than untouched SKS, the price is high to buy an AR and ammo prices are really much more expensive for 5.56...but u get 15 rounds, readily available mags/ammo if SHTF, if you buy an expensive one, it may be really, really reliable
5. As to the mags u r askin-i've seen those at Cabelas.
Some fitting will likely be required
The other day (2-3 wks ago) a member had a post here w/ fitting problems into original wood stock... so if yr hands grow from shoulders-try 'em, if they grow from butt.. --> don't