Congrats on the new sno machine.
If you're riding in the Midwest, I wouldn't mess with a powder track unless you want more after riding it a while. If nothing else, it will make you a better rider in the powder before getting the crutch of a big lug track. So much trail riding and a lot of low snow conditions compared to the mountains, you'll be fine.
The big lugs will not help your traction on hard/ice, lower your top end speed and cost you more at the pump and re-clutching as well.
I used to rail a ZRT and ZR with 121 trail tracks studded up through most every condition in N WI and the UP for years. You have twice the track under you already. Let er rip and save your $$ for gas!
As far as gear goes, drop any notion of a full face helmet and the heavy insulated gear you've had hanging in the closet for the last 15 years. MX helmet with a breath deflector and a good durable shell and some layers is where it's at...lol. For cold weather riding, the Motorfist helmets have the best breath deflector/face mask I've seen or used. Also a very light weight helmet. Downside is IMO the durability of them is not very good.