Jimny farm runabout, dont want to make wheel ruts.

Sorry it's taken a while to get back to this, work & lambing have taken a fair bit of my time (like all of it).
Thanks for the replies, the link to the tyres from Busta is great, 29-12.5-15 in the aggressive tractor tread looks a fair possibility, I hadn't seen those.
Argocats are a very capable machine but slow & the chain drives take a fair bit of keeping right if they're in regular work, I know a farm that used to run one & that place now has a Polaris Ranger which they fit tracks similar to those in the video in the winter.
I've been for a look at the tyres that were on the series 3 I knew that used to run in the same type of work, they're MASSIVE! 31-15.5-15! And they're likely available at sensible money so I've got one to play about with. I'm going to look at tyre & gear ratio calculators to have a work out if they'll take the gearing too high of if low range will be low enough for it all to be still effective. And I am concerned about wheel bearing/kingpin problems, it wont be doing serious off-roading but is going to a fair few miles. Still, an axle upgrade isn't out of the question!
And it's definately going to be a Jimny, I've bought one! It's an 02 reg 16v hard top, manual gearbox. Before any mods can begin though I've got to fix it, it's a cat C write off so will need a VIC check so I can get the logbook. Damage is minor enough, bumper & mounts will straighten & glue back together, radiator bust but a Honda Civic one has been cable tied in place to see if the engine is ok (it is) so that just needs some proper brackets sorted. And the front crossmember is bowed back a touch, it's not really affecting anything so I'll mabye leave it alone if it'll pass the VIC test as it is.