Rim offset, does it matter?

So I destroyed a rim last night, had to limp out, which made me very aware of the fact that I have no spare tire.  So Im looking to buy 2 new rims and a tire so I have a spare.  Should my spare tire be the same width as the front tire so I can use it front and back?  I would put the spare tire on the 1 rear rim that I have left, and I would buy 2 new rims that match for the rear of my ride if there is a better offset than the stock.  I am currently running 26x11x12 bighorns on the back and 26x9x12, so what rim if any would people recommend?  Just stick with stock or is there a better offset? 

what is the stud spacing and stock offset for the stock 09 ducks unlimited 700 rhino?

Also, if I had my spare as a bighorn 2.0 could that cause me problems due to different weights/imbalance when I had to use it?  Would save me a few pounds off of the total weight with the spare mounted on the ride 24/7, or is that something so insignificant that I shouldn't worry about it.

will bead lock rims be more durable?  I am in a very rocky environment, so something tough is what I would love to replace the stock rear rims with...I doubt I would want my tires sticking out wider, as thats what got me into trouble now, just a sharp rock in a rut, that caught the edge of my rim and flattened it at the bead...

Wheel stud spacing is 4/110. As for backspacing, you'll probably want to stay with stock rims. Don't know what stock rims are. but 5+2 is common for the aftermarket. That moves the tires out some. 4+3 is closer to stock but hard to find rims. You could use the 5+2 and remove the rear wheel spacers. The front would be a little wider yet. It also depends on the type of tire. It's tricky to get it right. Try checking the pic section, maybe theirs a rhino close to what you want and the info in the sig.
   Using the spare, I would put on the front. The rear diff is a locking type. If tires are different diameter it will make one spin faster causing stress. Use it on the front and try avoid 4wd.

I wouldn't change the diamater of the tire, just the width.  If I put on a front tire that is the same diamater as all the other tires, then I could at least us the spare all around, although not ideal for a rear, but it will get me home if I am days away...maybe I get the 5+2 spacing for the 2 rear tires, and take the 1 good rim left on the ride and use that as a spare. 

So what about bead lock rims?  Are they gonna be stronger/more resiliant to rock strikes just because of the bead locker plate?