Me too. In your situation, suggest you look for a 70 or even 75 series tire with diameter about equal to the rear tire and will also fit the front for a spare. Any 7" or 8" steel wheel that fits should do fine for the spare... coat of black paint if needed for the wheel.

My front and rear diameter is about the same... so a spare spec'ed for the front works for the rear. I have driven cross continent and never needed the spare... but glad I had it just in case for the long desert crossings.