My 2c worth:
- Mount is a limiting factor so you don't really want a long focal length cass; (Make sure you know what this is, none of the scopes listed is a cass.)
- A fast refractor is a good choice in terms of portability, and there are plenty on offer. UniPol has a Meade 80mm triplet in classifieds atm but you may need to change focusers for serious astrophotography. His gear is always immaculately cared for, (read "like new").
- The newts you have selected are faster, but fiddlier and bulkier and you may have issues getting back focus.
You have a few considerations to balance here but I'd make one comment.... don't rush it!
Good luck
Rom