Got a gig as a sound designer for theater, could use advice!

[Functional]

Hello, dear KVR members!

As the title states, I found myself an opportunity as a sound designer for a theatrical show, specifically, Alice in Wonderland, which is exactly the kind of thing that I would dream of doing. Now, there's approximately 7 months worth of time to pull it off. The director has the script, but apparently he has to add couple of characters in there so I have not yet had the chance to look at it. Anyways, this is a huge opportunity for me as I've sort of decided that I want to be a professional sound designer for theaters specifically. The aim is to get to the national theater of Finland, which is actually not so far fetched goal as Finland is clearly lacking talented sound designers that have a vision.

So now, I'll make this thread where I'll run my initial questions and probably will have more later on as well so I can just use this instead of creating multiple ones for all the questions regarding the gig. And without any further delay, let's get on to them;

Bitwig in Linux?
So, I've been lately looking at Bitwig for DJ gigs and then I got the idea, that I could run it with Linux to have a system I can rely upon, because Windows is too prone to crash and I would rather ditch the surround capability than to have a system that can ruin the show seldomly. All the sound design along with the mixing is done in Windows 8, Cubase 7.5, so I only really need Bitwig to run the waveforms mostly.

So the question(s) is/(are): is Bitwig + Linux a stable solution? Will there be any problems with multiple outputs (for surround) given that I will have a proper firewire audio interface? Is there anything I should consider if I choose to run the audio with this setup? How friendly is Linux generally with midi devices? I have experience with Ableton so I'm certain that Bitwig should be in itself capable of my needs?

Any recommendations for a proper Firewire Audio Interface solution?
This is something I will certainly need. I'd really like to have two options; one for about 400€ budget at max and another at about 800€ budget at max. It's sort of a long-term investment, but on the other hand, I don't earn that much so the more expensive audio interface will have to really bring me some bang for the buck. The I/O specifications at that price range shouldn't really be a problem, I really only need 4 outputs for this and for personal use I won't need much more inputs either. So I doubt there's really an option at those price ranges that would let me down in I/O section. Though I would love 2x XLR outputs for my own monitors.

I'll also need a midi controller with some sliders...
This one doesn't have to be expensive. Right now all I really need is just some sliders. For this gig, 8 should be already enough, though I would like 16 for personal / future use. Obviously additional buttons and such are welcome, but I'd like to keep the budget low on this, given that Bitwig & Audio Interface will make me broke by themselves.

The point is, I'll try to figure out a way to have scenes that I can transition between with the sliders. It's gonna involve a lot of programming, that's for sure. But if it's possible, I can add more human touch to the transitions as well and make it smoother for the actors as well, if required.

Any additional tips?
Obviously anything regarding the subject is welcome. I know communication will get me already far, and luckily, I work in the same house as the director does as a techy, so I get to talk with him on a daily basis and thus information always flows well.

Regarding the sound designing itself, I'll be using mixture of samples (and manipulate them, something I really love doing) and field recording of my own from various sources, such as violin or piano being played, birds flying around, the actors having a scripted dialogue full of nonsense, all kind of surfaces being hit by various objects etc etc. Anything I can come up with. And my "secret weapon" certainly will be STX-1280, digital tapestretch in Cubase (though I really need to get some tape recorders where stretching is possible), Skanner XT(this I'm not yet sure of, but going to experiment with it) & Padshop Pro. Those, honestly, go a long way on their own already.

Thanks in advance,
Functional