You don't indicate what equipment specifically you have - so that makes it hard to answer with regard to the PVR
Anyway, a few comments
PS3 getting material from PC is fairly straightforward, but there are a couple of pitfalls
(PS3) To get it directly from PC and play it directly, you need a media server such as TVersity running on the PC. This is supposed to send any video/audio that the PS3 supports directly to the PS3 - otherwise it will transcode the video/audio on the PC, then send to PS3 (note transcoding at 1920x1080 requires a very fast CPU)
I have run into problems getting multichannel audio to work, and many HD items you download from Internet require reprocessing to work well from PC to PS3 (either repackaging in a different format, or re-encoding of audio)
If you move stuff to PS3, a wider range of formats generally play more easily, BUT you are limited to 4GB FAT32 file size. Since much HD material is larger that this, a problem!
Now on the issue of playing or moving the original digital files to either the PC or the PS3 - the simple answer is "you can't"
THe files on the various PVR harddrives are generally copy-protected
Of course, you can downgrade the video by sending it out via S-video to PC, which will process it
Now there are workarounds for some equipment - rather than go into detail it would be best if you indicated what PVR you have (some of these options include Hauppauge HD-PVR, Expressvu R5000 mods, Motorola firewire output in non-5c areas)