After reading through all the replies it appears to me that OKC is the best trading partner. I think they would be interested in Rondo, and I believe Westbrook would be suited better at the 2 guard. I wrote on this forum back in August:
I do certainly think Scott Brooks plays a big role in the mismanagement of Westbrook and Durant, which is one of the reasons I think he should be fired. I don't think your point about Durant's regular season shot attempts with/without Westbrook tells the whole story though. After all, OKC's problem isn't in the regular season but rather in the playoffs, where ball movement ceases to exist (to the naked eye).
Let's look at 2011-12 (Westbrook healthy, playoff career high minutes at SG, trip to Finals), 2012-13 (no Westbrook) and 2013-14 (healthy Westbrook, MVP Durant, yet frustrating WCF loss). The reason I attempt to look at all three is because I think my perception of the Westbrook/Durant duo is being misinterpreted. I think Westbrook helps Durant as a player regardless of the position he plays. This is shown by the differential in the percentage of assisted baskets between Durant's 2012-13 playoff campaign and his 2013-14 campaign. Of his two-point FGM, 23.3% were assisted in 2012-13. In 2013-14, 53%. A similar differential can be seen in his percentage of three-pointers assisted. These stats suggest Westbrook takes pressure off Durant, creating more open/less contested shots for him. Westbrook's prowess as a scorer and an offensive threat are the same whether he plays PG or SG. When he's off the floor, Durant is forced into isolation.
My argument is more that Westbrook would help Durant even more so and be a more efficient player at SG. Now look at the 2011-12 playoffs. Westbrook played 33% of his minutes at SG, the highest percentage of his playoff career (and it's not even close; next highest percentage is 8% in 2013-14). During the playoff campaign, Westbrook shot career playoff highs in FG% and eFG% outside of his rookie year. Only his TS% was lower in 2011-12 than it was this year, which can be attributed to a far higher FT% this year (something that has little to do with him playing PG vs SG). Most importantly, Durant also found unique success with Westbrook playing more SG during the 2011-12 playoffs. His eFG% was 57%, 5.9% higher than his second career playoff high (which happened to be during this year's playoffs).
There's an argument to be made that the Thunder might just not be as good as they were in 2011-12 with Harden. Westbrook and Durant are, however, yet they played much less efficiently this year than they did in 2011-12. The argument I'm trying to make when I say "create more opportunities for Durant" has nothing to do with shot attempts. Durant already shoots about 20 times a game and there's only so many shots to go around. It has to do with efficiency and offensive fluidity, something that the Thunder's playoff offense lacks despite boasting three Olympians, one of which is the MVP.
I don't think we could get Ibaka for Rondo anymore without throwing in an appealing package of picks -- as I had proposed in the thread containing the quote above -- but OKC still has a slew of young players and picks that could entice Ainge to relinquish Rondo.
Here are a couple of proposals that I like.
http://espn.go.com/nba/tradeMachine?tradeId=pjfvcamBOS trades: Rajon Rondo
BOS receives: Kendrick Perkins, Harrison Barnes, Reggie Jackson
OKC trades: Kendrick Perkins, Reggie Jackson, Jeremy Lamb, Mitch McGary
OKC receives: Rajon Rondo
GSW trades: Harrison Barnes
GSW receives: Jeremy Lamb, Mitch McGary
http://espn.go.com/nba/tradeMachine?tradeId=kg7uaulBOS trades: Rajon Rondo, 2015 LAC 1st rounder
BOS receives: Kendrick Perkins, Noah Vonleh, Reggie Jackson, 2015 CHA 1st rounder
OKC trades: Kendrick Perkins, Reggie Jackson, Jeremy Lamb, Mitch McGary
OKC receives: Rajon Rondo
CHA trades: Noah Vonleh, 2015 CHA 1st rounder
CHA receives: Jeremy Lamb, Mitch McGary, 2015 LAC 1st rounder
This one is pretty wacky, but I like it...
http://espn.go.com/nba/tradeMachine?tradeId=pvk6vunBOS trades: Rajon Rondo, Kelly Olynyk, 2015/16 PHI 2nds
BOS receives: Kendrick Perkins, Bojan Bogdanovic, Shabazz Muhammad, Gorgui Dieng, Mason Plumlee
OKC trades: Kendrick Perkins, Reggie Jackson, Mitch McGary, Perry Jones III
OKC receives: Rajon Rondo, Ronny Turiaf
BKN trades: Bojan Bogdanovic, Mason Plumlee
BKN receives: Reggie Jackson, Kelly Olynyk
MIN trades: Shabazz Muhammad, Gorgui Dieng
MIN receives: Jeremy Lamb, Mitch McGary, Perry Jones III, 2015/16 PHI 2nds