Call Shaw and ask for Customer Retentions, tell them you are thinking of switching, but if the deal is right for all the upgrades you have mentioned then you will stay.
If you have been a long and loyal customer I am sure they will accommodate you.
You will need 2 lines for each pvr, and additional lines for each extra receiver. To ensure possible channel upgrades, make sure that each receiver is a 6xx series model- especially if connected to an hd (hdmi) tv.
The multiwsitch will be required with that many lines. They will install it professionally and to your satisfaction (dependent on installer and area though).
Good luck with the call!
Shaw Direct DVR830 / DVR 605/ 605, Sony Xbr65" 950E", Sony XBR4 850d, Oppo 980H, Yamaha 7.1 Surround, PS4! WDLive