heartbreakin, welcome to the forum. As you can imagine, a 6 ft+ person may have different needs from a 5'2" ft person. For example, you ask about pad size. Because I am short, I can get away with a ¾ length pad and even a ¾ length underquilt. It doesn't completely cover me, but it covers enough. Also, it's easy to add a little something at the foot end if necessary. For example, if, in addition to your ground pad, you also have a smaller "seat" pad.
But depending on the temperature and the person, that might not be needed. These nights I am sleeping outside the house in my WarBonnet RidgeRunner Bridge hammock with a ¾ length underquilt, The nighttime temperatures are in the low 50's and I'm perfectly warm with a light-weight (rated 35°) top quilt.
You know, it is all so subjective. When I go to sleep in a GE (gathered end) hammock, initially, I am comfortable on my back. Note that there are posts here and other forums advising that with a hammock, you may not need to model the same sleeping positions you use in a bed. You move around a lot in a bed because the bed creates pressure points that would not be present in a hammock. You may "need" to move around in hammock because it takes time for your body to learn it's not in a bed.
Anyway, by morning, I'm just a bucket of bones and soft tissue. I can fetal up on my side and breathe the fresh, sweet morning air.
The "double" hammock is usually a little wider than standard. That allows a TALL person to more leeway in turning diagonal to the center line of the hammock, resulting in the flat lie.
Again - no rules, just ifs, ish's, about's and maybe's, but many side sleepers prefer a bridge hammock design. The bridge hammock has spreader bars at the head/foot ends and creates a sort of shallow bathtub effect.
The challenge is, how do you find out what works for you? There is no "Hammock Central" store. REI mostly carries ENO (Eagles Nest Outfitters). The "Good" hammocks are made by cottage industry vendors. Even if I wanted to open a brick-and-mortar storefront in Bend, the margins of those cottage industry folk are so small, they could not sell their products to me at a price I could mark up to pay my rent. And you know, people would come in, try out the different hammocks, then go home and order what they want directly online from the vendor.
There are hammock hang conventions around the USA, and if you could attend one, you'd have an opportunity to try out various hammocks and see various setups.
There are also off-shoots, like the Amok Dramur "hammock" and the Haven/tent, that rely a great deal on the pad used inside. They may also be favored by side-sleepers. For me, because all my gear is self-purchased, there is only so much I can personally experience. So I focus on GE and Bridge setups.
