We have a Mountain Buggy Terrain in the garage which we got when our first arrived. Extremely tough and light, hammock style seat is great for off road, although that style is discontinued (no idea why). Don’t think you can fit a car seat to it though, and only really suitable for 3 months + IIRC. Mountain Buggy used to be a standalone company based in NZ but got bought up by Phil and Teds.
We actually ended up with a Phil and Teds too as number two came along sooner than expected and we needed a double. Ours is in great condition as little use, although the use it did get included hiking over the North Yorkshire and a fair few tow path 10k runs.
We’ve been meaning to Ebay it for ages, if it’s of any interest drop me a mail (in profile).