That seems a solid idea fluff wise. Yes some people try and exploit kill team to make it cheesy eg spamming a swarm, but Kill Team is about having fun with quick games. I think Kill Team is one of the best form of
40K to play. I like to try and keep a balanced list to counter this and that, but at the end of the day I run a list because it looks cool physically and can have a good backdrop story to go with it as well.
Points to consider in Kill Team:
Make sure you have something anti-vehicle; krak grenades, meltagun, or missile launcher etc, just in case someone throws a fast moving infantry killer at you.
Having something anti-swarm isn't necessary but is good insurance. Anything with a flamer template generally does well in Kill Team because theoretically you could wipe out 50% of the opponents list in one hand flamer blast etc.
Make sure its fun! Trying to be the big cheese with a cheesy list utterly ruins Kill Team for the other person. Kill Team is a great way to make your miniatures personal, you can convert each model and say well this is my specialist as you can see by his upgraded ... Give it a plausible history to show how the team fits together as a team. Kill Team is about giving the
individual model a personality that means something unlike the generic squad X has been obliterated oh well...
I hope your Kill Team goes well, looks individually great and you have fun playing it! Don't forget to keep Dakka updated with your progress if you want as well.