Gumbo is nothing more that soup over rice. Its what you have locally available and fresh. Good meat and fresh veggies make all the difference. I could list a 1000 things to look for but..... you know what you like and that is what you should make.
Its usually made with seafood or fowl with some type of seasoning meat to balance out standard roux. Usually the seasoning meat these days is used to maintain the depth of the gumbo's flavor due to the inability to build all 7 of the basic roux colors, white to red. I think its fine, its like an electric smoker and digital thermometers, it allows more people to enjoy what they might otherwise shy away from.
The roux should match the depth of the meats flavor. Light rouxs for seafood darker roux for duck. Its a balancing act.
The basic chicken and sausage gumbo is a nice peanut colored roux......
LOL so here I go again........
Case gave you the thread to my basic gumbo, Its pretty basically what I have been giving folks for years when they ask for a recipe. Somewhere in that thread is a chicken and sausage gumbo. Its the first one you'll want to attempt.
Remember its just a soup over rice, its the quality meats and fresh veggies that make all the difference. Well and the care given making it by the cooker.
Good luck with it, however you do it I am sure you'll be happy.