1.
Here and
here are two good sources for you to check. The first one has a chart that shows how the checks work and what styles you should absolutely never wear together. It also has a list of clothes and what style they have, but I think that some of the names of the clothes might be wrong. The second one just has a list of all the clothes in the game and their style, and this one should be correct on all clothing names (just go to the top under the Clothing bar). Go through your catalog and see if there's anything you can use.
2. Gracie acts like other special visitors and has a chance of appearing once a week every week. That being said, you do need to pass her check four times, and you can easily go weeks without seeing her, so I'd highly recommend you start passing her checks now, unless your either a time traveler or you just really don't care about the Emporium for whatever reason.