Is it possible to record/dvr with Roku/HuluPlus/Amazon/regular tv without my DirecTV box/dvr?

I am considering switching to Roku/Netflix/Hulu, etc. to save money. The functionality I'm afraid of losing is my DVR-- I watch a lot of shows on NBC that I am often not home for, and would prefer not to watch them all via my laptop (nor HDMI hookup)-- I want them on my tv the same way I've had them available with DVR. Anyone know if or how this is possible?? THANK YOU.