Well I ride Cervelo, and love them...props to you for picking two Canadian companies.
Guru will custom build your frame for a extra couple hundred dollars(2-300), worth it if you plan on keeping the frame forever, they have a bad resale value.

With that being said, My vote goes for whatever is for you, price, size ect. For me I would go with the P2k, it looks more aero dynamic, I dont know if it is or not.