By the time we were choosing nav lighting during our build we were stretched pretty thin financially and so we decided to go for a very inexpensive solution. I bought LED bulbs from https://superbrightleds.com that are typically used in cars for the tail lights. The up side of this is that they are cheap and many types fit a standard size fixture. When we bought the bulbs originally it was something like a 36-LED bulb and they came in red and green and a couple other colors. This was sufficient. Its been two years now and LED bulb technology has come a little further so why have a 36-bulb when you can have a 45-SMD LED setup!? More power! Each bulb was like $25 but comparatively for normal aviation stuff this is still dirt cheap. I am quite pleased with the new bulbs as they are brighter and are look cooler than the old ones. The daytime photo doesnt do it a ton of justice, but I'm sure they are more obvious at night.
Before (36-LED bulb) | After (45-SMD LED bulb)