After a run-in with some sort of steel braided cable, one of my tires now needs replaced. I am mere millimeters from needing a whole set, so I thought I'd take to opportunity to swap for a set of steel wheels and tires.

I am running stock alloy rims with 265/55R18's now ('99 Disco with ACES).

Can I swap to a 16" rim with a decent size AT tire without needing lift?

 

The largest tire without lifting is 245/75/16.

You might want to consider Atlantic British for a set of steel wheels, they are having a sale

http://www.roverparts.com/Parts/3030A.cfm