I am in progress with the same kit, building it as a mid version, up to now I have left off the air filters and not started on the tools. I found conflicting information during research on this subject regarding equipment and colours. There are detailed articles on the following sites, both different.
http://www.wwiiscalemodels.com/cgi-wwii/ultimatebb.cgi?ubb=forum;f=80
http://www.missing-lynx.com/articles/german/mmtiger/mmtiger.htm
Further reading revealed that there were a variety of Tigers operating at any one time, with variants ranging from early, late early, early mid, mid mid and mid late.
I have decided on a mid version without the air filters but no major modifications to the interior.
As for colours, the kit instructions are next to useless, so I have followed the above articles in parts and used artistic licence for the rest.
Hope this helps.