Floridian said: Thanks for all the info! I appreciate you taking the time to give me such detailed help. 
Floridian, I checked a site today to see if there were any developments, it's been busy by the look of it, a diversity of grafts have been carried out, mainly ornamentals.
In particular there are three grafts you may find useful:
Try pairing rabbit ears cactus with dragon fruit
How to pair Succulent with dragon fruit
How to graft cactus into the stem of Epiphyllum
Generally speaking the site is well worthwhile visiting just to see the plants being grown and grafted to/from.
Cheers
