Congrats, from one Cherokee owner to another.
I have a 1972 PA28-180 G, learned to fly in it, still have it, love it,simple and flys easy.(love the johnson bar flaps)
Not fast but reliable, great for pavement or grass runways.
You mentioned wanting to change the outside lighting.
I can recommend the whelen led tail beacon-like a red flashing laser,
it had when I bought it a white belly strobe,
I put in a Whelen led landing light, blueish color ,much brighter than the old GE 4509
bought led replacement bulbs for the position lights, I just put the red under the red lens and green under the green did not buy the clear lens as some recommended, works and looks great
no burn outs, very,very low draw on the led's.
Have fun with it.