I am a huge Rondo fan, but I would consider the following trade:
Detroit: Jeff Green, Carl Landry
Lets start with Sacramento. They have been known to have their sights set on both Rondo and Smith for a while and I think that they would jump at a chance to land both of them. The trade leaves them a little bit short handed at SG, but they would pull together a very impressive big-4 of Rondo-Gay-Smith-Cousins, considering their current lack of assets.
Detroit hasn't made up its mind on what to do with the Smith-Monroe conundrum, although it seems to make sense to everyone else in the league that one of them has to go. In this scenario they get out from the Josh Smith contract and get back a piece that fits quite well in Jeff Green. They will need to take on Carl Landry's contract, but he could very well bounce back from injury to be a good 3rd big man off the bench.
Milwaukee gets involved because Sacramento has so few assets to acquire big name players. They can't surrender a pick until 2018 and their only two assets are SGs. I can imaging Ainge needing both to get a deal done, but I can't imagine them both on the same roster along with Bradley, Smart, Young, and Thornton. I also don't want to take back Derrick Williams. I think Milwaukee could be convinced to get out from Sanders contract by taking a very good young SG and Williams. McLemore actually fits that team very well. He has the athleticism, but he can also stretch the floor with Jabari. I think Knight-McLemore-Giannis-Parker-Henson would be a scary young core. Also, lets be real, the Bucks are going nowhere this season and there are quite a number of prospective centers who are suppose to come out in next year's draft.
The Celtics get good value for Rondo and Green. Stauskas could be an excellent backcourt mate with Smart and can also play with Bradley. Rondo's departure opens up the space for our young PG. Jason Thompson is 6'11 and 250, so I would have him back up Sanders! at center.
The trade would leave us big-heavy and weak at SF. However, I think a few more moves could be made by Ainge. I imagine he could call up the Knicks and offer a swap of Bass & Thornton for Amare by including Bogans. The catch would be the inclusion of Shumpart who could become our starting SF for the year. I'd even give up a low-value pick for Shump, like the Philly 1st. I would then do what the Knicks won't and waive Amare so that he can go be a productive big off the bench for a contender, a pièce de résistance for OKC.
At the end of the day, the Celtics could look as follows:
Shumpart, Young, Wallace
Sanders, Thompson, Zeller