Celtics: Collins
Spurs: Prichard, Kornet, Walsh, multiple second round picks
Celtics then sign (free agent) Austin Rivers.
Personally I don't feel this is an All In move. Collins isn't really the type of player we need. We're needing a defensive center and someone who can rebound. Plus this is giving up way to much for a player like Collins.
Could get a player like Jalen Smith from the Pacers. He's only 5 million and has an extra year. Would probably be had for couple seconds and we have our TE from Grant Williams. If you want throw in player like Kornet. This could also be done with a player like Andre Drummond who is something we need.
If I'm going to send some real assets and going All In it'll be for a young center we can resign and have him make a difference. Ship Pritchard, Hauser, Kornet and Walsh with a couple seconds for Nic Claxton. You only do this if you know you can resign him or extend him now.