[Asterisk-Users] Best SIP phone for high quality telemarketing

[Shaun Dawson]

Hello,

  I'm interested in opinions about the best phone for high quality
telemarketing use(very heavy use with highest possible quality sound).
 I'd prefer that the phone be SIP, but I'd consider anything that will
work with Asterisk.  I think I'm going to need both deskphones and
softphones, but I'm particularly interested in desk phones right now.

  I'm particularly concerned about voice quality, and phone durability
for hours of continuous use.  It should also be able to be used with a
quality headset.

Anyone have any thoughts?

thanks,
  Shaun