Hey, Helen,
By full-size, you mean just not a compact one, or also that it should be reversible? As we covered reversible in your last question, I will only focus on non-reversible ones here. And btw, you simply don't want a three-wheeler, did I get it right? As I believe a Baby Jogger City Mini GT2 could work here, but if you just don't want a three-wheeled stroller, I can understand.
From the four-wheeled models, look at the Valco Trend SPORT (Sport has inflatable wheels so better for bumps), an incredibly large seat. I also liked the space of the Oyster Zero (Gravity) which is very very light, but the suspension as ok even for my gfamily's trips over a lot of grassy terrain. Also check the Britax B-Motion line if you can get your hand on one, though I don't know how available that is in the UK anymore.
Last piece of advice - it is not a bad thing to get a reversible system and then change it. You can always sell it, and it is rather normal, as as I said before, the needs change over time. So maybe don't tr to chase the "perfect" model that has it all, there's no such thing. Go with what you need now, like the Salsa, and you'll see what you'll need later on. I did the same.