Fluro to Fireline leader ???????

I wanted to get away from using so much fireline this season ( due to its visibilty ) but have not found anything that fishes as well for me ( Castability, Memory, Sensitivity ) I have decided to try to add a fluro leader to the fireline ( best of both worlds) I see from a past post here that most are using a double Uni knot to connect the two. My question is how long of a leader are most adding? and do any of you add super glue to the knot for added strength? I’m looking at using this set up for almost all plastic techniques ( Texas rig, Jig worm, weighless worms, Ect. ) Thanks in advance for your response.