I'm having a hard time finding those tires anywhere, but Cooper does list a Discoverer Snow Claw winter tire with the following specs (Link to Discoverer Snow Claw:
Cooper Discoverer Snow Claw):
LT275/70R18 - Size | 125\122R - Load Index/Speed Rating | | E - Load Range | BLK | 7 - 8.5 | 8 | 11.1 | 33.35- Diameter | 54 - Weight(lbs) | 3640 | 16 |
I believe the tire you are asking about is this tire marketed by third parties (e.g. Dean Tire) under the Wintercat brand label.
I have misgivings about the "off branding" of the tire you mention, but even more I have concerns about the size.
The tire you are asking about has a diameter spec. of 33.35 inches - larger in diameter than any tire Toyota recommends, and probably would result in clearance issues (i.e. rubbing) when mounted on your LC200. It will also reduce your towing "power" - in short, it is too big.
I would look for a tire from a recognized name brand manufacturer in a size more appropriate to your use case - my preference would be for a 285/60R18 XL, P285/60R18 or LT285/60R18 tire.
HTH
Edit to add:
I just re-read your OP and find that you are currently running LT275/70R18 BFG KO2 tires. Do you have any clearance/rubbing issues with them? If not, then you could stick with the same size for your winter tires.
And yes, I would recommend new wheels (and TPMS sensors) for the new tires since you are planning to run two sets of tires - one set for winter and the other all other times.