I am using both decks against lv20. Nice and fast and easy. Not necessary to use Marik as getting RA out will give you 6k score already. Just use Mokuba's monsters as tribute folders if you get a bad draw. I often tribute his White Eyes to get my Sylvans out to make the duel end faster. Need to be careful of that Fur Hire deck tho.
This is not really a farming deck and is just one of mine. But after winning all 3 of the tag levels 3 times, I have 3 of almost all the rainbow packs and got 3 of the things I really care about: Shining flare wingman and swords at dawn. Idk why, but I always seem to have better luck getting the SR and UR cards at the lotteries by drawing them one by one for 30 coins each.