We'll need a bit more information to answer your questions.
Firstly, 1 rec is 1 defence and 5 hp. That's the easy one.
As to whether rec or absorb is better, well, it depends.
What level are you?
What is your toon for? (PvP, grinding, boss tanking, farming ... )
What sort of budget are you looking at?
As a defender/guardian you can make use of a lot of different stats:
Tank builds can use absorb, rec, dex, wis
Battle builds can use all those plus str, luck.