Eric,
First read the post "everything you need to know about replcia speedsters" right here on SOC. Then, depending on what info you are looking for, there are tons of books and websites that have answers to just about all those questions. As for kids in the back, I'd have to say that's probably not going to work. There really isn't any room back there. Engines, possibilities are endless. However, most of the originals had 1600cc engines located in the rear, very much the old VW's. Look at the builders websites (again under the "Makers" tab here) and they have lots of info and pics. These cars are replicas of old roadsters and are pretty much "second" cars for most. I drive mine everyday practically but I do have another car. As far as reliablility, they are custom cars, NOT factory made! Therefore their not going to give you the reliability of a new Honda or any other new car. Just surf around this site and you will see pictures and threads that should answer just about every question you may have. Good Luck - Mickey