Thanks for the replys,

Autozone, Advanced Auto or Walmart don't even list Dot 5 on their websites.

Since I'm purging the existing system filled with Dot 3, I'm going to err on getting too much.

I'm going to get the 6 - 12oz bottles, that way the leftovers will be in sealed containers for future use.

Should I hook up the vacuum bleeder and suck out as much as I can before adding?
Or just add the purple stuff and bleed each wheel until it looks like only the purple coming out?

Thanks