IP Phones

AssassinX

Hi, I am just new here and I am building a lab for my CCNA voice and then will continue to build it for CCNP Voice. I would like to ask for suggestions on what Cisco IP phone/model, what are the minimum specs required and the recommended. Also, will all cisco phones work with all protocols like SIP, MGCP, and H323? If I buy thru ebay or 2nd hand/refurbished phones, does it include the phone license? Any assistance would be much appreciated.