you dont need to bring the french family anything, because you are also doing them a favor.
regarding to the sex, i do think a female is better, but sex doesn't matter at all.
go to a big supermarket, then you can find the toilet box right next to pet's food, or ask a sales person in the store they are willing to helps you
i don't suggest you to prepare 水晶猫砂 for your kitty because kitty is too weak to use it, it is more for adult cat, meanwhile it is to heavy and to expensive.
sorry i can input chinese, anyway i hope those above could help you. good luck with your pet.