Should I get a Deca for my Gemini unit?

I have recently installed a Gemini receiver as a replacement to a Genie in my basement.  I have been running this unit as wireless but the connection is iffy.  I have a Directv coax running to this location.  How do I go about getting a Directv Deca unit to see if this will solve my problem?  How much will I be charged for this unit?

Thanks, Ron M