You might look for a Combi Coccoro. That one might be available in the UK. The Dionos are good in some respects but not in others. They are really heavy. However, they fold for easy(ish) transport. They are tall, so if you attempt to rear-face them, they do not fit on all planes. It should work in the bulkhead. Rear-facing will keep your baby at a more comfortable angle, so it's preferable. However, it will also prevent a seat in front of it from reclining, if it even fits.
My preference over a luggage cart is to travel with a lightweight car seat that hangs off of the stroller handle. I usually needed a stroller wherever we went at that age, and that way I can eliminate one piece of gear by not using the luggage cart. Our two strollers used for travel are the Babyjogger City Mini, which is built like a tank. We never even cover it. Also, we have used the Uppababy G-Lite. Both of these have made countless trips with no stroller bags or anything fancy and have survived beautifully.