Funny you ask about this powder and bullet. I did load development yesterday. Hodgdon lists 24 G as minimum, and 26 G as Max with compressed load for 69 grain Sierra hpbt. Being that 68 is lighter, these numbers are fine. Don't worry about the compressed load thing, its not that big a deal. I shot the following 3 shot groups yesterday out of my 20" 1-8" twist AR with Lake City Brass, CCI400 primers loaded to magazine length of 1.841 at the olgive.
Charge: 24.7
Velocity: 2777
2751
2768
Measured: .32"
Charge: 24.9
Velocity: 2812
2789
2787
Measured: .89"
Charge: 25.1
Velocity: 2805
2833
2846
Measured: 1.4"
Charge: 25.3
Velocity: 2844
2852
2848
Measured: 1.01"
Charge: 25.5
Velocity: 2895
2868
2862
Measured: .81"
I would imagine you have a longer barrel, and so you should see higher velocity by a little bit.
I'm gonna reshoot 24.7, 25.5 and prolly throw 3 more up in .02 as I saw no signs of pressure.
As far as your other choices of powder. I have all except RL 10, and have tried all. Seems like I try most powders in all my rifles and most end up using Varget.
Have fun!