Hopefully I can help out here, as I have the
FL Studio Signature Bundle, and have enjoyed tinkering with it over the past 10 years or so. I'm by no means an expert, but I can happily recommend FL Studio as a powerful, user-friendly, attractive and feature-packed DAW (digital audio workstation).
Simion and Phyre mentioned over-pricing of creative software, and I do believe this applies to the Adobe Creative suite (Photoshop, etc.), but not to FL Studio; honestly, for the amount of features and polish you get, FL Studio would be worth the asking price (in my humble opinion) even if Image-Line
didn't offer lifetime free updates (which they impressively
do). The development team are constantly working hard to deliver new features and better performance — most of which we get without paying another cent (although some special plugins are developed as an optional, payable extra). I very rarely buy software, but even though I go for long periods of time without using FL Studio, I never have regretted the purchase — it's a wonderful piece of software to have.
The good news is that even the most affordable FL Studio package ought to be perfect for the project you're describing — and you can always upgrade (it'll only cost you the price difference, you won't have to pay for the program again) if ever you want/need the additional features of the more advanced packages.
I'd be happy to lend a hand from time to time if you need a bit of guidance through any stage of your project; I've done all of what you've mentioned, so I can assure you it's not too difficult to do, but help is available if you need it.