Anthony Morrow
Anthony Morrow is somewhat interesting. Excellent shooter and good at creating scoring opportunities with movement off the ball. I'd be more interested in him if he was either more prolific as a scorer (12ppg in 31mpg in GSW) or better in non-scoring areas.
Non scoring areas -- Defense is below average but decent. Rebounding slightly below average. Passing is similar to James Jones, nice team orientated, always make the extra pass, but not much beyond that.
Travis Outlaw
I'm not that interested in Travis Outlaw as a backup for Paul Pierce. However, I do think he's an excellent option to replace Glen Davis. He gives Boston that perimeter orientated athletic power forward that they lack when matching up against teams like Atlanta (Josh Smith) and Orlando (Rashard Lewis).
I don't think Outlaw is as good a scorer at the three versus the four because he lacks a quickness/explosiveness advantage there. He isn't the most efficient scorer either, and can be taken out of the game by a good defense team (especially at SF). His defense is also slightly below average but that's mostly down to a lack of effort rather than defensive potential.
Split The MLE
I like the idea of splitting the MLE between two players. Rasual Butler is very good name here. Also, Dorrell Wright depending on how his performance level fluctuates as the season progresses. Raja Bell. And our own Marquis Daniels.
Three more interesting names have player options -- Kelenna Azubuike, Mo Evans and John Salmons -- I don't think I trust Salmons enough to pay him the sort of money he'll ask for though.
The one note on Rasual Butler is that he's a weak rebounding wing. So is Ray Allen. And Paul Pierce is gradually declining. That three man wing rotation would be fairly vulnerable on the glass and force the rest of the team (bigs, PGs) to make up for their flaws. So, if Butler is a main target, then I think it's important that team gets a fourth wing who can rebound the ball well (like Marquis or Wright or Azubuike).
Mike Miller
Mike Miller would be the player at the top of my wish list. A decent scorer, excellent shooter, very good-to-excellent rebounder and a very good passer. Below average but serviceable defensively mainly due to his size + length.
If Miller was available for the MLE, and I think there's a good chance he will be (not a certainty though, then he'd be my top choice to backup Paul Pierce and Ray Allen.
Then try to sign a minimum contract wing like Keith Bogans or Ime Udoka or Quinton Ross, someone who's an above average defender, to provide a different skill-set behind Miller. Someone that can give some minutes when necessary.