Thanks for the feedback. I think I would like to stick to black or tan, mostly because I feel like I would be changing my color scheme if I do gray. I just need to have my FI try on some suits for me (he has both tan and black) and get an idea. I'm leaning towards black suit for him, and then black suit/vest for the GMs with a matching tie to the BM dresses. Still not sure if I would do white shirt or tan, but at least I can narrow it down a little. I knew in my head that black and tan would look wierd... I just have a hard time choosing!
Also, since my wedding is in February it's not like it will be blasting hot, so linen may not be necessary. I'm also having 3 ring bearers that all have black tuxes already from previous weddings... so that would be a plus.
FYI, for those that want just pants (no vest/suit) Kohl's has a Marc Anthony line that has different colors of linen pants for $28! I was trying to make these work but ultimately I want a little more formal look so I will need a matching jacket/vest. Although I might snatch a few pairs for my FI to wear while we are down there