If you are concerned with average the safer bets are probably Rolen, Blalock, and Mora with career averages in the mid 270s to mid 280s. In contrast Branyan and Stewart (small sample size) are career 230 something bats and Reynolds and Feliz sit in the 250s. Hitters tend to revert to their norms so don't put a ton of emphasis on a short six week period to open the season. If Branyan hits 235 and Blalock 275 for the next month or so (their norms) you won't really see it looking at their cummulative stats, given their starts. The inordinate impact of slow/fast starts fools fantasy owner perception every season.
Of the guys in the higher average group I think Blalock and then Rolen should provide the most power/production. If you are concerned most with production then Reynolds or Branyan are your choice. IMO you're essentially just looking for a patch until Aramis returns so current health is all that matters. Don't worry too much about injury histories at this point as you can simply replace this pickup if he goes down. Of your options I'd roll with Blalock.
MVP****AL07,AL05,NL04,ALNL03,ALNL02,NL01,ALNL00,AL99,ALNL98,ALNL96 RIP Cammi
Cmon Bud NOW is the time to sack up and force feed an Olympic style drug testing program down Fehr's fat throat and save OUR game from these blatant cheaters!