LeadMD is a great partner that I have worked wit in the past. Also, Wunderman LA is another great agency
Thanks Dan Stevens for recommending Grazitti Interactive, we'll ensure to help you with more quality work.
Nice meeting you via community post.
Our in-house Marketo certified experts have developed various responsive emails on Email Editor 2.0 and helped Marketo customers with Guided landing pages. I would be happy to showcase our work on a call and discuss your requirement in detail.
Please drop me an email with few convenient time slots at firstname.lastname@example.org
Grazitti, Perkuto, and Knak are the main places to go to.
If you want a freelancer, then maybe they'd respond here or you could find them through other means and just make sure they know Marketo's requirements for templates.