Best sneakers for achilles tendonitis and pronation?

Go to running store: Most podiatrists can watch you walk/run and pick the best shoe for you, or recommend an orthotic with a specific shoe brand. Another good option is to go to a high end specialty shoe store for runners. Often podiatrists help train their salespeople.

An orthotic: To me would be a more important "treatment" than a specific sneaker.

NEED FOR SUPPORT!: Most shoes aren't always what is bad, usually it's the crummy insoles they come with! with achilles tendonitis and pronation, prescription orthotics are the best bet, but you can try arch supports like spenco polysorb total support (http://www.Spenco.Com/products/footcare/poly-sorb) and otc anti-inflammatories (like aleve). If these don't help, see a podiatrist.

No: There are no pathologic specific shoes. Purchase a cushioned neutral shoe and focus on strengthening your entire lower extremity.