if you are working in a budget I would get regular Koralia powerheads and upgrade them down the road.
lights - tek T5 used is a proven affordable performed.
for the skimmer look for a used one: Not all skimmers are created equal. I would go with an Sro2000, seaside cs2, JNS sk2, or bubble king mini 160 if you feel like spending. These are all proven performers. There are others I don't know as well like skims which I heard is great. I haven't read up on the bubble magus skimmers.
I purchased an SK2 for 180 shipped