If you are trying to load "normal" 20 gauge loads ie: 7/8 oz @ 1200 fps, Lilgun is not a suitable powder.
The first load you quoted is a 2 3/4" Magnum load.
The second load is a hyper-velocity field load, and will not work as a reduced load.
Availability has forced you to pick poor choices of hulls, wads, and powder, for normal 7/8 oz loads.
For a novice reloader, the best and easiest to use hulls are Remington STS or Gun Club, and Winchester AA.
Use Winchester AA20 or Clay Buster CB1078 wads.
Any of these powders will work for 7/8 oz @1200 fps loads.
Alliant: Green Dot, Unique, Herco and 20/28.
Hodgdon: Universal
Winchester: WSF
For higher velocity 1300 fps loads:
Hodgdon: HS6, Longshot
Alliant: Pro Reach
Michael