A320 or B744
It depends on whether you want long haul flights to far away places, or short haul regional flights to not so far away places. It depends on whether you want to fly for 12 hours or fly for 6 hours. It depends on which aircraft you like and love and want to get to grips with.
You`ve got your freedom, so make your choice - the wonga will work out about the same in the long run - and yes as Skallywag said - any airline worth its salt will do your type training for you, having said that, perhaps having a type rating already MAY give you an advantage when applying for a position which asks for type rated pilots on a specific type.
You may find it prudent to choose one type say Airbus A320 for example and then upgrade as you go along in your career, or, start on the 73 and work your way up to the 74 via the 75 and 76 - sort of keep it in the family.