Oxford & Jepp used to have a deal where Jepp printed and distributed Oxfords manuals. They fell out. Oxford now distribute their manuals through Transair.
Jeppesen bought the copyright of Air Atlantique's / Pooley's manuals (its a bit confused).
Both sets of manuals are in book format rather than loose leaf. I can't guide your choice, I'm afraid, I've only had a quick look through them, but they seemed very comparable.