My RV-3 already had position and strobes when I bought it. Mine are cut into the wing tips. Apart from stringing the wires down the wings, It would not be a huge project, but there may be some easier options.
Mine did NOT have a landing light and I needed it to be N-VFR, so I installed a cool LED one I got from Aircraft Spruce. The amp draw is super low, and it provides more than enough light. It has a 2-position toggle switch which gives you steady light or flashing. I flash when taxiing for better visibility.
I cut mine in just above the air inlet scoop on the underside of the cowl. It fit nicely without too much fiberglass work....piece of cake.
Send me a message and I can email you the part number for the light, and send installation photos if you are interested.