Thank you for participating in our online forum community here! I'm sorry to hear you are having some trouble finding your remote while setting up your Slingbox. As far as I know, Directv receivers all use the same IR coding so you should be able to select any Directv model, I would suggest the HR22. Another thing to check is the remote settings of your cable box, most Directv boxes have the capability (within the menu) to switch between RF (radio frequency) and IR (infrared). The cable box will need to be set to IR in order for the Slingbox to be able to control/ command it.
Hope this helps!
The Sling Moderation Team