Leg room they will be fine headroom look for a non sunroof unit if you go this direction.
I hate to say it but at those sizes you should be looking at full size I'm 240 lbs and considered a big guy quads and upper body (not gut lol) but when compared to a lineman 6'7" 300lb + fast wrecking machines make guys like me seem small....lol
I'd probably look to a sequoia, newer tundra, possibly fj80 but I get out of the 4runner and its sometimes unexpected by others... my buddy I race with is 6'7" bit 190 height is his issue he dlesnt have a family so hes driving a cj5 now but had a tundra before and he fit height wise pretty good...
Keep us posted as to what worked out I think it would make a good thread oR post for others.
Whether it be a Toyota or whatever......
Discovery II sold, on to a 99 Toyota 4runner sport build.