I tried to get the Gunslinger Girls mangas but the vendor didn't have them. I'll have to pick them up from RSI.
Make sure you get the two omnibus collections (containing volumes 1-6) for Gunslinger Girl as well. ADV only released volumes 1-6 when they had the license and the listings for their edition of volume 1 & 6 have been removed from RightStuf. Seven Seas will release volume 7 and up as single volumes for those that collected the original ADV releases.
The two Gunslinger Girl omnibus volumes should be here before Friday. I just finished the three HOTD books and can't wait for the fourth to be released.