I don't think one is stronger than the other on the side links. The kit comes with steel turnbuckles and rod ends.
I've been running SMC packs for blinky. They have a new one 6100 60c I believe it is. Ran strong for me.
Springs in blinky a safe spot is 20 fronts and 20 sides, exactly what comes in the kit. Most of the time I run 18 or 20 sides and 20 or 22 fronts. Almost never 22 sides and very rarely 18 fronts. Lube green is the only bottle I carry. So maybe grab an extra set or two or 20/22 fronts and 18/20 sides?
Spares I'd say springs, both side and front. Maybe an extra set of old school arms to be safe. Bearings are good to have on hand. Maybe just to be safe front axles and kingpins.
Anything other questions feel free to ask.