I actually ordered a power door look/keyless entry and alarm kit from J.C. Whitney. Don't remember the price, but it was a good deal.
The aftermarket design comes with the actuators and they are very powerful and quiet. There must be at least 100 ways to mount the actuator in the door. They come with all you need to do the job.
If you are handy with tools, I would suggest you do this yourself to save some time and make sure it is done right. Putting the keyless entry in conjunction with it is the way to go. Most alarms have keyless, so you can get a power door lock kit from whitney, then an alarm from anybody. Don't remember the name brand of the alarm I got from whitney, but it was good quality stuff, and works perfect.
You can get just a keyless kit from whitney for like $30 if you don't want the hassle of the alarm system.
I can't tell you much more, as you will have to see for yourself when you get involved. I am pleased with the conversion.
I also installed power windows from a 81 vette. However, I put the power door lock button in the same location on the new door panels as where your standard window crank would go. YOu can put the switch anywhere, or just hide them and go keyless all the time by only using the remote.