Very likely, every entity we currently have will be on the R&D tree somewhere. However, expect something like the Mando armour to be near the very end so you'd have to work your way through all the lesser armours first.
As for getting a set, well get me an SSD and you can have mine!
It is probably more desirable for the RP value (and rarity) since so many people want to roleplay as Mandalorians. In terms of armour values, while it is functionally better, the difference is effectively insignificant considering armour absorption values. (set of Mando: 27, set of HBA: 22)