ya u need a good relief pitcher for sure. your lineup could use some tweaks too and your SP seem pretty solid too. you definately should look at trading for a closer. yovani gallardo is doin great and can hit so his value at this point is decent and with chris capuano comin off the dl he will likely be movin to the bullpen or they will end up movin claudio vargas too the pen also hunter pence seems like he is a solid fixture in that astros lineup so hes got decent value as well. If i was you i would try to deal manny and gallardo for a solid closer and outfeilder such as jj putz or a mediocre closer who you could get for less just too hold the fort right now.
Is that bench, or Util? Seems weird for it to bench. If it is, I'll second the idea of trying to move Manny for a stud closer. If it's not and Pence is util, might have to sell Gallardo or Blanton with him to get a stud and a decent replacement, or get a middle tier closer and decent replacement for just Manny to put in util if possible.