tyres sizes and quality

im running a P38 range rover diesel.

I am not sure what to do ive got a set of 16" 7J alloys currently fitted which are hideous with legal tyres. and ive got a nice set of 18" 8J discovery 2 alloys that need tyres.

has anybody tried 255/55r18 mud pluggers? the ones I was looking at are MARIX puma which are like the old SAHARA style remoulds.

do they withstand the abuse as the side walls would be shorter obviously as the rim is bigger.

or should I stick with the old faithful 265/75r16 same design, theres not a lot in the prices.
truck is converted to coil springs and has a 2" lift.

any opinions?

Stick with what you know is best bet 👍