BeautifulBrunette- What did you do with MacDougal?
I'd be happy with who you've got closing. BK posts solid numbers and is on a great team. Other than that, you've got two guys who platoon as closer. Marte should probably close for the Sox, but Manuel's afraid of using his top lefty exclusively in the 9th. He'd rather play by matchups. Lopez will probably get most of the opps as closer, since he's the righty out of the pen. If I were you, I wouldn't really bother with winning the save category. Unlike ROTO leagues, I don't think knocking off a category in H2H is a bad strategy. If you continue to lose the save category even though you've got Lopez now, too, I would heavily consider this, and pick up relievers who have extremely low ERAs/WHIPs to lower those categories (and add K's, as well). You apparently have already begun to do this with Rafael Soriano.
To answer another of your questions, Marte's a keeper. He gets a save now or then, and has an ERA in the 1's, and a WHIP in the 1.0's. I would not touch any of the options the other guys have listed on WW. Most will destroy your ERA/WHIP categories (Lincoln, Carter).