P265/65R17 or LT265/70R17 ??????

I've decided on Michelin LTX A/T2 tires for my 2005 Double Cab TRD Sport, now I need to decide whether to stick with the stock tire size or bump up to a LT series 70 (Michelin doesn't make an LT in the 265/65 series). The P265 weighs in at 41 pounds with a tread depth of 14/32" and the LT 265 is 53 pounds with a tread depth of 17/32".

My truck gets driven on the road for commuting, but also logging roads and off road for fishing, hunting, and camping.

What say you all????

Also, if I go with the LT265/70R17 can I still use my P265/65R17 as a spare? The LT 70 has a diameter of 31.7" and a revs per mile of 657. The P265/65 has a diameter of 30.6" and a revs per mile of 681. That's a difference of less than 4% in revs per mile and in diameter. I would think that is pretty minimal difference, and I wouldn't think that for temporary use of a spare that it would cause a lot of problems, but I'm interested in what other more knowledgeable members think.

Thanks for the help, I appreciate any opinions!!!!

JD