Tivo Series 2 Standalone with DirecTV?

I now have Comcast, but I am thinking of switching to DirecTV. I have 3 Tivo series 2 standalone Dvr's and a HD DVR through Comcast for my HD tv. DirectTV is offering their own HD DVR for free which is fine to replace the Comcast DVR. My question is on my other 3 tv's will I still be able to use my Tivos with the other DirectTV receivers? They are also offering a " Whole Home DVR" and I'm also curious if I will be able to use my Tivos with this feature? I've asked DirectTV but have gotten conflicting answers from them.