If you are trying for simple and scalable, why not impose a kind of "luxury tax" of say 15% on the top 15% of posts with a set timeframe, say 24 hrs (noon to noon).
-money set aside in pot
-given to top 15 posts with content deemed worthy (under $100 initial payout)
-voted on immediately after the announcement of the contenders for the payout (vote for 24 hrs)
-voted on by everyone, 1 vote per session (you can only vote for 1 post)
-highest vote getter gets receives the most reward, scaled down from 1 - 10
The best way I see to set up the secondary vote is an additional ONE VOTE button. This button would be used only to select the top 15 posts under $100, with payout percentage TBD (To Be Determined)
This will give you a vehicle to recognize minnows without having to change the voting structure. It also gives minnows a chance to have equal say in determining a payout, with the 1 vote rule to determine the 2nd chance winner. Thanks for your great work on Steemit.