They'll all be owned a leasing company. Airlines simply don't own aircraft any more.
They have a bunch of 320s and 321s which were due to be returned in the next couple of years as their new 737s were delivered, so your best deal is likely to be with Boeing, who now have a minor gap in their order book.
No, Tui (the airline formerly known as Thomson). One company that stands to benefit considerably from the demise of Monarch.
It's a shame though, we extended our summer holiday and flew back with Monarch instead of Ryanair, and the whole experience was considerably more pleasurable.