I think the first one is
Sex In A Can by Hana Hikaru. Most definitely MA (no YIMs).
I know that I've read the second one too. Inupapa has everyone living in the same house (though they mostly come in as strangers to each other). Kagome was working in a bar, but later gets fired. Her family had turned her out for not agreeing to an arranged marriage (I think). The modelling part comes in where Sesshomaru and Kagome are recruited to play "The Lovers," but they aren't and need to act like it. I've tried a couple of searches with keywords on FF.N, but I'm coming up empty (unfortunately). Do these details sound similar to the story you're thinking of?