Lux-
It sounds like you need to do some forum searches. There are some great threads on this forum that will answer your questions.
Having said that, we need to know what you currently have for an alternator. Do you know what capacity the one you have is?
Personally, I'd say it never hurts to upgrade, as it sounds like you've got some high-draw items that could benefit from the added capacity. I just upgraded from a 36amp (?) to a 94amp alternator.
Here is the thread on the wiring discussion we had:
http://67-72chevytrucks.com/vboard/s...d.php?t=757426
Also, lots of good reading in this FAQ article:
http://67-72chevytrucks.com/vboard/s...d.php?t=119379
I'm not sure how much advantage there is to a 1-wire upgrade, but the upgrade to an internally regulated unit seems to be worth it.