In that amount of time you can learn HTML/CSS on your own and get a design you really want out of it, while saving $1k+. I know doing a startup full-time means you're probably also bootstrapping. If you think you can put backend dev on hold for a week to build up the front end yourself, here's a great link that helped me: http://htmldog.com/

And as a side note, you may want to be finding a cofounder anyway (single-manned companies are hard pressed to succeed), and a frontend dev would be a great balance to your backend work.