Honestly though, I dont think your suggested solution would work or work properly since the OP is really talking about defeating some sort of analog copy protection. I think your suggested solution isnt designed to defeat copy protection / scrambling,...but I guess I could be wrong,...
I personally cant really speak to that end as I suspect open discussions of such things may be discouraged.
I will say this though:
I have two dedicated Media Center systems (living room and bedroom). Between the two I have a server that automatically receives recordings from the Media Center systems and serves up recording to them. Recordings are made with a number of QAM tuners plus a Hauppauge HD PVR USB unit and Hauppauge Colossus PCIe card. These are analog devices connected to my cable set top boxes respectively (and Media Center systems) and are capable of recording up to 1080i / 720p as well as standard definition. They can do this from even premium channels (HBO-HD, Showtime-HD and so on) and they seem to ignore DRM completely by design so all recordings in Media Center are unrestricted.
These devises are perfectly capable of copying a library of analog VHS tapes. Some people use them to offload recordings from a rented DVR. I have used them to copy old Sony Handy Cam home videos and store them on our local home server. I cant say how well it would do with old analog protected VHS tapes though.
Recording are made on the PC in a native AVCHD / H.264 format (options are .ts, .m2ts and so on). Any modern computer should be fine for making and playing these files.