I'll tell you what I know. I'm sure there are others more knowledgable than me who will chime in, but I asked the same questions myself as I was interested.
Super Dwarf retics are from a super small locality of retic, getting around 6 foot. A dwarf retic usually means it is a super dwarf/regular retic mix.
Note--there aren't any morphs from the super dwarfs, so if you see 'het albino SUPER dwarf", it's not really a super dwarf, just a 'dwarf' since it's a mix of the two.
The issue with dwarves is they have a lot of wiggle room size-wise. Some can be very small, some end up very large. I've heard if you get a line of dwarves with parents and grandparents that are all similar sizes you can get a decent idea of how big they will get, but it's still no guarentee. Plus, it seems most people just have a straight up mix from a super dwarf to a normal, or dwarf to a normal, so you get some pretty random genetics going on.
Generally they SHOULD even out around the middle, but they can still get pretty big. I've seen a dwarf that was over 12 foot, and a sibling/clutchmate to that adult that was still around 6 foot at the same age.
I think it's best to expect them to be large, and prepare for that, but be pleasantly surprised if they end up at a reasonable length! Better than expecting them to be small, and having to scrounge together a big cage on the spot!
