Powell is the least interesting of the two to me because of the signing of Rob Johnson, Powell is a 29 y/o right handed catcher who was a first round pick in 2004 by Oakland. After a tremendous NCAA carreer in which he was named to the NCAA College World Series Legends Team, in Oakland he was in the shadow of Kurt Suzuki. Both catchers drafted in the same year. Suzuki got the bulk of the playing time and was therefore, promoted more aggressively. After two years of injury set backs in the minors ( 2007-2008) he became the back-up catcher in 2009 and served in that role since, appearing in about 40 games a season while hitting .207. Powell is another one of those weak hitting defensive catchers, he caught Branden Dallas' perfect game and has a 39% caught stealing rate. He can play some 1B and I wouldn't mind if the Mets claimed him but realistically he's an older duplication of Nickeas/Johnson while only having one more option left.
Jai Miller is the player I hope the Mets win a claim on, the 26 y/o right handed outfield has yet to break out in the majors but if his minor league numbers are any indication of what he can do, this is a kid who can play center, steal a base and hit for power. In four seasons at AAA he's averaged 21 HRs, 23 doubles, 11 stolen bases, 63 RBIs with a BA of .271. He's 523 minor league games in center field and 205 in right field, along with a hand full in left. Last season with Oakland's AAA affiliate he put up some impressive numbers, still has only played in 28 major league games between three organization ( Fla., KC, Oak.).
Miller, meanwhile, spent the majority of 2011 with Triple-A Sacramento, hitting .276 with 32 home runs and 88 RBIs in 110 games. As a September callup in Oakland, the outfielder went 3-for-12 with one homer and two RBIs in seven games and, by season's end, was expected to compete for a starting-outfield job come spring. source Athletics.com
Miller seems like a perfect fit for what the Mets need especially since he still has options left, I think the most vulnerable player on the 40 man roster would be Armando Rodriguez. The 23 y/o power pitcher is in his 5th season with the Mets, his second on the 40 man and is yet to pitch about A+ ball. Last season in St. Lucie he made 16 starts with a 3.96 ERA/ 1.18 WHIP and averaged almost a strike out per inning.