You can still find shops that are certified for R-12, but it'll be a huge pain in the butt if you plan on keeping it much longer. For the $150, it's a lot better to just convert it to R134, it'll save a lot of headache down the road.
ProjectLM has some good stuff. eBay price, all CREE LEDs with a nice warranty :D. eBay stuff is nice to test out setups though, but I've also had some of them with less than scrupulous wiring...
Maybe a little? It makes sense since the fluids are going to be considerably more viscous and won't flow through the dampers as readily. I can't say it's super pronounced for me, but it makes sense from a mechanics perspective.