My tire theory is this-- if a VX'er ain't gonna' listen to reason by keeping individual maximum tire weight to no greater than 44 lbs each; and is hell-bent on getting excessively heavy tires, then I say "GO BIG; or, GO HOME!!!"
Thus, my ultimate recommendation for MARLIN was the G/Y M/T-R with Kevlar in 285/75R18 (35" O.D./65 lbs) in BSW and mounted on the Stock OEM 18x7 rims which would greatly help reduce front wheel well rubbing issues to a bare minimum due to the OEM rim's proper offset/backspacing. For MARLIN's "spare", I would recommend the very skinny and lightweight 35" O.D. Mickey-Thompson sand tire of "Baja Pro" in 35x10.0-15 (35" O.D./40 lbs) (Part #2555) and sells for $220 each at www.PerformanceParts4Less.com. This combination remains my best recommendation for MARLIN.
However; despite my best efforts, MARLIN chose the smaller 275/70R18 (33.4" O.D./63 lbs), and saved a whooping 2 lbs per tire. For a "spare", he'll use a 32" O.D. Grabber AT2 from his previous VX set. Yes; it doesn't match the O.D., but as long as it's installed on only the front axle, then it should be OK in an emergency. With the beefy M/T-R with Kevlar, I suspect MARLIN will never get a flat no matter how hard he tries (then again, MARLIN can find a way to break anything).