We also did PGS/CGH for our most recent fresh cycle ttc a sibling - in our case, b/c we'd had 3 mcs with DE/DS, one before and two after our twins, and would have done anything to avoid another loss. So in addition to adding tons of immune tx/blood thinner, we also did PGS/CGH, though not for purposes of gender selection. We do have b/g twins from a prior cycle and had no real preference on gender - just wanted a healthy baby. (I probably would have chosen boy if we had to choose, and DH probably would have chosen girl, but we didn't need to choose and again, neither of us really cared and we wanted to use the best looking embryo, not one of a particular gender - having a HEALTHY baby of either gender was really the only thing we cared about.) Though we did agree we wanted to put in the one best looking embryo, I also asked to know the gender of that embryo on the day of transfer and they were happy to tell us; they didn't seem to have any prohibition on telling us. I think one person who did DE at our clinic did gender selection, so I think my clinic allows it? Not totally sure though as I haven't asked them that question.
Honestly, DE is such a crapshoot anyway, I would really put in the best looking embryo(s) even if you do CGH. GL