Often someone does an HF mock draft where they go to each team's boards to vote. Doesn't look like it was done this year.
There are a few ways to do this. One option is to make a 10-option poll. Let people suggest different realistic trade scenarios between now and July 1 and mention who they'd pick and just list the best suggestions. For examples:
Option 1: trade 19 OA plus Vilardi to move up, draft Mintyukov
Option 2: keep 19 OA, draft Pickering
Option 3: trade 19 OA to move down + get pick, draft Bichsel
Alternatively, you can make multiple polls. One poll for people asking if they want to trade up, down, or stay. After the first poll, you can make a second poll of players available in the range people voted for.
Third option is to have one poll, allow multiple selections, but ask people to pick ONE option of move up, move down, or stay, and pick 3 prospects.
I'm reluctant to suggest the third based on the reading comprehension of some posters, but it would be the easiest to set up.
Unfortunately there's no way to number your top picks