Beginner - what should I buy?

[Ryan Raphael <raraphael@comcast.net>]

I'm a beginner looper... well, not even beginner, complete ignorant  
novice!

I guess I'm a songwriter, and I was interested on creating loops  
live, not necessarily
recording them ahead of time and then playing them live.


Mainly, I want to know:

-If I make one loop, can I create another one and have them play over  
each other?
-Is there a delay in the loops replay by a couple seconds?
-Which is better, the Boomerang or Jamman. It seems the Boomerang has  
more options for live looping than the Jamman.
What I really care about it accuracy in its looping.

I guess, but remember – I'm totally new to this. I haven't even  
bought one yet.
Thanks to anyone who can help.

-rar414