So you are logging turbine time, that's good. Any chance of moving to Captain of the lear?

If you were about to get fired, I'd say move to a regional. If not, keep doing what you are doing. If you ever do move to Captain in the lear, that would be gold. Turbine PIC helps a lot, then maybe you can move up to a bigger charter or cargo. Make contacts in the corporate world. You might meet someone looking for a lear FO where you'll get more hours or have that ability to move up. Stability is probably a good idea these days, and you can justify your decisions well during an interview ("why didn't you fly with a regional?"). I know quite a few people that have "leapfrogged up" in the corporate world, in fact, these have been the most successful pilots I know (out of all of them, regional drivers, etc).

You do realize how few pilots actually fly international cargo in 777s and 747s right? It might not be a good idea to set your sights quite like that. Maybe a better goal is just an airplane as big as or bigger than a 757, at which point you'll have the experience they'd likely be looking for at FedEx/Ups or anyone else that flies the biggest aircraft.