Build on Yii + MongoDB + CoffeeScript Startup

I'm an accomplished developer who took on one freelance project too many in addition to my day job. I need help finishing some core features of this project I just don't have time for. You will benefit from being able to communicate with me on a technical level -- no dealing with product people or management. You should be expert level both server- and client-side PHP and JS, preferably with experience with CoffeeScript which this project uses extensively. Also experience with Sass and Haml are a plus because they are used in key components. The project is a business that provides a JavaScript snippet to partner businesses (B2B) that spawns a widget on their page showing what businesses are available to a consumer to help that consumer install products the consumer is purchasing. Picture for example: - You're on a TV retailer's site. - You're about to purchase a TV. - The sidebar says "there are 5 installers in your area that can install your TV." - You click the sidebar and you can then book an appointment with the installers. **Most importantly** you should have **extensive** knowledge of browser compatibility issues and writing cross-browser HTML/CSS/JS. Being as this widget is dropped into sites whose visitors run the gamut in terms of browsers, and as we don't want to destroy those sites with our 3rd party JS, you must be expert level in this regard. Only people with very high ratings will be considered.