I would 100% do Turner, Sully, Pressey and 2nd or two for Gallinari. I don't think the Nuggets will be able to get a ton more than that because he is an expiring contract in a year when more teams will have cap space than players that deserve it.
I'm pretty sure we could sign Johnson, do this trade with Denver, do the trade with Golden State, then Sign Jerebeko followed by Crowder if we do it in that order I think there is the cap space available to cover the difference in salaries in the Gallo deal.
If we can't work this out I would love to have Wilson Chandler for Zeller/Turner.
I'd also trade two of our bigs plus Turner for Faried which wouldn't solve our roster imbalance but I'm just a Faried fan.