Most inexpensive spare tire option 2007 Single axle trailer

[Lennyp04]

Our 07 X1 will be coming home for storage for the first time ever. The trip is roughly 90 miles from the lake to home. Our trailer has probably 30 miles on it since it really never went out a 5 mile trip from our house to the ramp. I think for the trip home though it would be great to have a spare tire. I just want a very basic rim with a good tire. It's a single axle so its the 6 bolt but I don't know any of the other measurements such as centerbore, offset, etc. if someone could help me figure those measurements out, I'd appreciate it!

Thanks!