Give Scott at
www.trailertireandwheels.com a call and discuss it with him--very knowledgeable about all trailers and wheels.
If you have a 2-axle trailer, suggest you upgrade to 17.5 wheels/tires and be done with tire worries. You would be looking at $2100 +/- and also the spare, but it is a one-time deal and that would fit the full-time lifestyle.
I assume you have 8k axles? If not, the 17.5s are probably way overkill, and you will have to think about 16" options. TTW can help you make a decision--they can send everything to you mounted and balanced.
Joe