I got a Sigma 50-150 f/2.8 and a Meike MK-RC7 flash trigger. I'm testing them this weekend and will be posting reviews very soon (RC7 first). Initial impressions of the RC7 are neutral / slightly negative. Of the Sigma 50-150, it's positive.
RC7 review posted here (not as bad as I initially thought): http://betterfamilyphotos.blogspot.com/2010/09/meike-mk-rc7-wireless-flash-trigger.html