I wanted to have potlights installed one the first floor of an older house, but am completely confused by all the conflicting material that I've read. I am hoping to get some straight answers: 1. Installers fall into tow groups. Some advertise $80/light, others $120. Is there really a difference?2. Do I need to have a new line put in for the potlights?3. Is it better to buy my own fixtures so that I know what I'm getting?4. Most people seem to advocate line voltage but others low voltage. Is one really beter than the other?Thanks.