Thanks so much for all the replies, keep them coming!

Budget? Well, as cheap as possible! I would opt for *A if I could find something reasonable, but not so far! I suppose these dates are the worst possible- summer, a long stay and December all combined.

So far I think the best will be Zoom or Air Transat. Nothing is cheap, though! I am exhausted from looking already.

On the subject of charters, does anyone have advice on shipping baggage? Zoom's allowance is one bag that weighs 20kgs. Luggage for 4 months over 3 seasons will be way more than that.

Thanks for all the great tips.