It matters what ship you are using due to the technerf functions.
For example, it would make little sense for a Liberty Rogue to be owning to Gallic Royal Navy ship. So even if the Cougar is one hell of a beast, it cannot be used effectively by a Liberty Rogue ID'd player. If you use a GRN ship with a LR ID, you get a nerf to 10% of your powercore, meaning your powercore only regenerates at 10% of the normal rate, rendering you incapable of PvP.
If you want to get a ship, get one that has 100% or 90%. If you're good, maybe even 75%. Anything below that will make PvP very difficult.
Look at this Tech Chart for specific information on technerfs.
Get a Raven's Talon at Battleship York in New London, Freeport 4 in Magellan or Thunder Bay Depot at Ontario.