Ours is a t4 camper Holdsworth xl
In the back it has proper 3 point seat belts so ok for child seats
My advice would be get a tdi if you can afford it as we have a 2.4d and its still slow (proper converted campers are bloody heavy)
other than that look for others types of campers as T4's are not as reliable as the VW followers would have you belive.
ps we are selling ours and prob going to get a toyota Hiace and convert it ourselves