The best way to collect assets is getting a higher draft pick, but if KG isn't retiring, it would be better to wait till 2014-2015 to let PP/KG/Jet retire and tank like mad men.
But if KG is retiring, it's time to tank, just not blowing it out nuke style.
DA should try to trade KG for a bad contract + young player + first rounders: KG for Turkoglu and pick, Charlie V.+ Kyle Singler and pick... right after the trade, KG files retirement papers, and they save a ton of money. KG then comes back to the Cs to be big men coach (I know it'd be difficult, but wouldn't it be great?).
Then The Captain is traded to the Bulls (yeah, that sounds terrible) to finish his contract there, alongside Bass, for Boozer (extra year) and Rip Hamilton. The Bulls should include their Charlotte 2014 first round pick (top 10 protected in 2014, top 8 in 2015, unprotected in 2016) for the money they're saving, and the versatility of Pierce+Bass. When PP is a free agent again in 2014, sign him on a two year team-friendly contract to let him retire in Green.
It would be ideal to trade the Jet, but I'm not sure if they will be a big market for him. The same with Lee, if any team is asking for him and puts a good offer, deal done.
Keep Rondo off the court until after the ASG, D-Rose style, you need to be bad to tank, and that worked out just fine with the Admiral and Duncan. No need to rush him or Sully.
Keep T-Will, Crawkward and Shav, and play them a lot alongside Bradley, Green, Melo and this year's rookie(a big who can stretch the floor to pair with Sully would be great).
This way you would get three first round picks in the 2014 Draft, and the ability to get great prospects and/or package Boozer+pick+prospects for a star. Then you sign Pierce as 6th man star and you have a great team, maybe a contender for the 2014-2015 season.