I also bought the Foundry sourcebook 'The British in India' (slightly dented copy for a pound!). Great reading and quite invaluable as I'm a newcomer to that period. I likewise purchased some British Infantry in Airpipe Helmets, plus some in flannel shirts. I'm assuming from the source text that British dress and headgear could be quite varied. Hopefully I'll be able to field these two units alongside each other without being too historically inaccurate? If anyone knows any different then please feel free to comment.
I'm also thinking of buying the 'Sharp Practice' rules. I played these with an Indian Mutiny scenario when I first joined the local wargames club and thoroughly enjoyed it. As yet I haven't come across any other skirmish type rulesets for 28mm Indian Mutiny, but again if anyone can suggest any I'll definitely check them out.