AFT Galley
Dear Gents If I could possibly add a few things etc to this conversation. One Thing is Key to this is which particular Gulfstream are you referring too etc?
The GIV and G450 mainly are offered with AFT Galleys, Forward galleys are not the the normal and if its a GIV a lot of the radio rack will take up essential space, however haven said that I have seen some great G450 with a partial galley in the front and one in the back.
GV-G550 as its a long range aircraft depends on your client etc.
Charter arrangement
(Forward Galley has great advantages in the fact that the Crew can give privacy to the clients) and if there is a Fwd Lav and crew rest or work station this is a fantastic option. I would advise though to not have a full sink vanity unity takes up too much room.
If its a Private client its basically up to them what they prefer but a forward galley does work well.
NJE and NJA opted for AFT galleys on their GV-G550 fleet and I think they found it often difficult on long range flights as the FA was constantly in the Cabin. The other thing is the noise created when food is being prepared.
It would be interesting to see on their new globals what they opted for