newbie needs help

[Josh <josh@undertone.com>]

ok... Basically this is one of those annoying newbie posts of the type of: 
"DUH... UH, which looper is the coolest?" But actually I hope to put a bit 
more intelligence into this question by first describing the scenario in 
which I want to use the looper and then getting suggestions as to which 
looper might best fit my needs from you all...

What I want a looper to do:

Basically, I want a songwriting tool. I am a guitarist and I want a 
looping 
device to help me discover cool riffs on the guitar, bass lines etc... I 
have no intention of using the looper in live performance, but I do want 
all of the functions available in an included foot switch. Basically, I 
want to use the looper to come up with parts for songs. I want to be able 
to loop parts POST effects and pre-amp in my rig so that each loop might 
have its own tone and FX qualities, also, I use stereo effects so it needs 
to have stereo input/output. I have very little need for things like 
slowing down, chopping up or reversing the loop as I don't want to use the 
looper as an effect box in itself, rather just as a sampler/songwriting 
tool. If it has some bonus FX stuff then that's cool in case I ever decide 
I want to include it in my live rig. Another cool thing would be if it had 
the ability to switch between "loop sets" so that I could have one set of 
stuff looping for the "verse" and then switch to another set of stuff 
looping for the "chorus" or "bridge" etc... so that I can use it to come 
up 
with arrangements for songs. Another cool feature would be the ability to 
add and remove layers from the loop so that for example I could get the 
"verse" looping but get rid of the main guitar part so that I could "solo" 
over it... etc...

My price range is around $500

Please let me know which looper would be best for my needs. Thanks!!!

Josh