Do the PVRs on the market all work with Freesat?
Yes, you can buy 'generic' DVB-S (digital video broadcasting - satellite) PVRs, but they usually lack a decent EPG.
If you wish to watch the same programme as the main TV, you can use an RF connection from the satellite decoder to the second TV.
However, you may be happier using another satellite decoder in the second location - but to do this your dish's LNB will require multiple outputs (a Quad LNB has four, for example) and a separate satellite-grade coaxial connection from LNB to new receiver. This would allow you to watch any channel you wanted at the second location, however, and with better picture quality.