Which unit for getting into looping ?

[Borhane Blili Hamelin <borhane@cgocable.ca>]

Which unit would you suggest for getting into loops ?  I'm a guitar player,
and I'd like to use loops for combining multiple parts live ( So it's more
about recording and playing over/with multiple parts than running a 20
second loop ala frippertronics...)

I'm looking for sub 300$, both used or new. ( don't really care..)  Any tip
???  I was looking at the roland sp-303 ( I thought about triggering loops
via midi footcontroller), any opinion ?

thanks