Can you make a Cisco phone with with the native SCCP (skinny) driver in Asterisk? Yes. Does anyone openly recommend it? No.
Reason being that the SCCP support is limited and your phone may not do everything you want it to. Whoever told you that SCCP somehow sounds better then SIP when both are using ULAW sounds like they might be drinking the kool-aid. If there is a difference it's in the faulty/buggy/crisco firmware.
And that brings me to my next question: What model Cisco phone? Cause not all Cisco phones are Cisco phones. A good chunk of them are rebranded phones after Cisco bought some random company. They also have a non-unified provisioning template config, different firmwares, different SIP support, etc.
So, I guess i'll add to the voices you've already talked to, using a SIP cisco phone would be better then skinny. However, using a Polycom or Snom would be best.
Cisco only really likes to work well with Cisco.