K, well here's your problem with those wheels. The only ones in the proper bolt pattern (that I saw) for a Ram 1500 are 22x12 -44 offset which you aren't going to clear with just a leveling kit. It's way too wide. Plus I wouldn't run a 12.5 tire on a 12" wide rim. It looks ridiculous IMO.
I ordered my rims/tires from Bully's Performance and had them all shipped to Sumas, WA and then took them across the border myself. They shipped them fully mounted and balanced with TPMS sensors and then with the tax coming across the border I paid a total of about $3300. I would definitely recommend talking to them and getting a quote. Email either Andrew or Jeremiah at firstname.lastname@example.org
If you do get wheels/tires installed in the states and come back across the line they probably will notice and you better declare it if they do. Otherwise you'll be in trouble. It's not worth the hassle to save a couple hundred bucks.