I play with a Logitech PS3 imitation controller on my PC and I love it. Yes I believe it will never be as efficient as using a keyboard/mouse but it's great for the reasons that you mention. My suggestion would be to go out to a best buy pick up one of these controllers for $20 and try it out for yourself. That way you can become acclimated with the playstyle in advance and figure out what you like best.

Also... I have an HDMI cable for my laptop so when I feel like being on my couch I can just plug that into my 50 inch tv and play from the comfort of my couch even without a PS4.