Plastic hood is 100% fine. No difference, as long as it's opaque, fits, and shades the lens. I use one on my 124.
Case is totally not necessary. I got one with mine, removed it, tossed it in the closet, and haven't seen it since. I got a nice little bag made for the digital folks that neatly holds the camera, my Luna-Pro SBC and all the accessories I normally carry plus film. It's the smallest bag in my set of bags except for my digisnapper, and the camera lives in that.
Enjoy. If it's as good as the 124 you'll love it. I love mine.