I'm a certified Knot Geek, I actually have tons of rope around my house just to fiddle with for knot tying. My wife thinks I'm nuts for tying knots all of the time but if I'm old in a wheelchair, I'll never be bored.lol.

To your question, I use spinning reels exclusively and have never needed a backer line. But I'm panfishing/freshwater fishing with Mono, so I really don't need a backer line. A blood knot has always been known as a VERY good knot BUT hard to tie...especially out in the wild(on a boat with a little wind, breeze, boat rocking and shifting etc). A Surgeon's Knot would probably work well and it's much easier to tie in these conditions that you'll face. The Albright Knot is a good one and it's much easier to tie than the blood knot. The Uni Knot isn't quite as strong as the Blood Knot but it's a little easier to tie.

I'd either go with the Surgeon's Knot or Albright Knot. I think the Surgeon's would be the easiest to tie and it's a good enough knot...especially if this is for freshwater fishing. Saltwater fishing usually demands Blood Knots.