I have a feeling you're seriously underestimating the amount of work it takes to get the blimp part working...
I had the option to do a blimp project as my minor (software engineering, college)...
Thats ~5 months of full-time project time, I did some quick searches and abandoned the idea...
The blimp, which would've been nearly 2 meters long I believe, could carry an atmega chip.. with breakout board, 2 engines and a tiny servo, with a tiny battery. The weight didn't allow for anything more than that. In case I'm not quite clear what I mean... you need a very large balloon to carry a couple of electrical scraps, a full-sized arduino, regular servos and such a large controller for communications??... you'll need a giant blimp, one you will likely have to build yourself. Better start saving for the required helium too, it'll likely be more expensive than you'd think.
(for reference, the blimp I'd have available, the arduino based hardware that was created as part of a previous project, was smaller than that RC module, and thats including the engines and battery).
Not trying to crush you, just hoping you realise all the hurdles you'll need to overcome.. which are quite a few, several of them are quite daunting.