Wouldn't 1.25" wheel spacers combined with +60mm offset factory wheels be nearly the same offset as +25mm aftermarket wheels?
Something to keep in mind is the Icons are a half inch wider than stock wheels (8" vs 8.5") which I believe is in the same range overall as the Bora 0.75" spacer with stock wheels. I've tried many different permutations looking for the Goldilocks combo including: stock 08 LX wheels, stock 08 LC wheels, stock 13 wheels, stock 14 wheels, stock 16 wheels, Rock Warriors, Icon Vector 5, and Method 309 wheels. On the stock wheels I've run no spacer, 0.75" Bora spacers, and 1.25" Spidertax spacers. For tires on the 200, I've run 275/70/18 Duratracs, 35x12.50 Toyo AT2s (tried KDSS relocation brackets on these - still didn't like it), 285/75/17 Ridge Grapplers, 275/65/20 KO2, 285/60/18 KO2s, 285/70/18 Ridge Grapplers, 285/75/18 Ridge Grapplers, 285/65/18 Cooper AT3s, stock size Dunlops, Blizzaks, Michelin, and Nexen tires (came with the Lexus).
After all that research/fun, my recommendation for the biggest tire with the least hassle on the 200 series Land Cruiser if you want the biggest tire with the least hassle a 34"x11.50" tire like a 285/75/17 or 285/70/18 Ridge Grappler on a stock wheel with a 0.75" hubcentric spacer like the Bora or an Icon 25mm offset wheel is ideal. I don't claim to be an expert, but I have experimented a lot and this formula has worked perfectly for me. The alignment is key as well, and a good off road shop like Slee is strongly recommended.
One quick side note: On the LX, there is a bit more room to play with since there is no KDSS, and I ran the 34" KO2s totally 100% stock - no spacers, no alignment, no AHC tricks. The only thing required was removing the front mud flaps.