Search boxes for individuals content types
Found an answer in the end if anyone else comes here searching for a solution. Turns out you could do what I wanted with the custom searech module I mentioned in my question. If you go into modules in the admin area there's also a custom search block module that comes with custom search that can be enabled. This gives you the ability to add as many blocks with different confiurations as you please. You then just go into blocks in structure and configure to your hearts content for each block then use those blocks where you want, job done! Just need to work out how to change the template now!