I love both names, a lot, and they would make a great sibset.
I adore the name
Jasper; we almost named our first son
Jasper this past
May. (We named him
Wesley instead after getting so much negative feedback from friends and family.)
I like the idea of
Jocelyn, and I may add it to my list. My g-ma's name is
Joyce, so that would be a great way to honor her, since I don't particularly like the name
Joyce.
Jocelyn Sally doesn't flow well at all, but I do like the meaning of it.
Jasper Henry is nice.