1. I wouldn't suggest Zara (quality, pencil thin lapels, short jackets)
2. I wouldn't suggest black (rather charcoal, black reads 'funeral' to me)
3. Denim couture sounds like a bad idea
4. Your height and body type dont dictate jacket size (mainly shoulder/chest fit are important, much can be tailored)
5. I suggest you just read these forums for a while, do your research. If not, you'll have many regrets in the future.
I read a lot, and still have regrets!!!!!