I don't think you need to specify. As long as you have the time and means to care for each animal properly you can have one BP or 100 different animals of all types.

Just make sure to do your research before purchasing, especially regarding the longevity of the animals. Many reptiles live to ripe old ages (maybe even outlive you!) and you need to be prepared to take care of them for as long as they are still breathing.

Think to yourself if you really thought long and hard about getting the turtles, or if it was more of a spur of the moment thing because you got all fired up about them one day (not saying this is the case, but it happens).