Hi there. I've come across a lot of paid sites that sell templates but they really are only asthetic templates that are differing in color scheme, graphics and design etc. Are their template sites that sell whole purpose built site templates with functioning code etc? For example an imageboard site or a content site where u can for example upload pictures and people can rate them, comment on them etc. I want to build the later as a website and need to know where to get started, basically. Thanks!
All the places that you saw selling themes design those themes themselves based on with their own ideas. So they are good in designing but may be just not thinking in line with your ideas. If your requirement does not match any of those themes then the best was forward is to contact them and they will be happy to design a custom built/purpose built theme for you - as long as you pay them. Developing or integrating iImageboard/rating etc/ is fairly easy and they should be able to do that as long as you know what you want.