While I'm unfamiliar with the Hi Mountain kits, I'll comment on the pork vs venison question.. You can really use any portions you want, as long as you end up with a final fat percentage of around 30%. You likely have lean venison (0% fat), and can use pork shoulder (25% fat) or straight pork fat (100% fat) to obtain the final 30%. So if you like more venison flavor, you could do 70/30 venison/fat, or for more mild flavor 40/40/20 venison/pork shoulder/fat.
When I refer to "pork shoulder" I'm referring to the standard twin pack pork butts like you get at Costco but with the fat cap removed.
Even 60/40 pork shoulder/venison comes in low on the final fat content at around 15% total (unless they're including the fat cap, which would put it somewhere north of 15%). My opinion is if you're going to cut venison, you need to throw some straight pork fat in because it's hard to get the total fat percentage up to where it needs to be with just pork shoulder alone.
And however you cut it, don't forget the NFDM (non-fat dry milk) to the tune of 1 cup per 5lbs. It really does make a world of difference in the texture and moisture retention. It's possible the Hi Mountain kit already has it in it; something to look into.