I missed an approximate budget a lot in here, and I wasn't sure about easy transport - a small fold (not very compatible with all-terrain features) or just an easy one? Anyhow, I would definitely advise looking for those that fold with their seat and have larger than small wheels. My first thought went to a Joie Finiti, or perhaps Versatrax or Aeria. Not small after folding, no, but ok for what they can do. Just the canopies are not the largest when in lie-flat mode, but you can easily solve that with a universal sun shade.
You can also check the Cybex Mios which is not an all-terrain and has no extreme hood, but there can also go a sun shade, and the seat is very nicely sized - just the wheels are smaller, but we were using them on grass, too. That is the car boot-friendly, less all-terrain option, of course.
Also, remember that VERY FEW strollers can take more than 15 kg in a reversible seat - it is simply not large enough inside, the more so if the stroller is reasonably compact. A large-seater with a reversible seat, but also a larger stroller, would be the Kinderkraft Everyday (full Kinderkraft Everyday stroller review here), or even the Baby Jogger City Premier (which is a bucket seat model).
I would actually start with a cheaper stroller system at the start, and passed on to a non-reversible seat around 1-1.5 years of age, and you will be much better off than trying to find all-in-one. Try to think more about the budget and what is around you, and let me know if you still have questions!