A few reactions based on pronunciations...
JOL: Strong, rugged, logger type. I could see him as either red-headed, blond, or balding (w/dark hair). An authoritative person, and probably an oldest child. Extensive book-knowledge and well grounded. Hmm... I think that's it. Oh, he might have a beard. Happily married with a nice family. Has a wood stove in his house, whether it's used or not.
jo-EL: Athletic, nice, and smiles a lot. Easily distracted. I picture a je-EL as being a lot younger than a JOL, for some reason.
As a sibling for Peter, it doesn't work to me. Peter seems like it needs a longer name to make a matching set. *quietly votes for Conrad*