Partner with proven ethical sales people rather than B.S. artists. As a technical person working a job, the best way for you to meet such people is to work with them in a technical capacity. If your current job doesn't give you opportunities to work with the best sales people in your company (including traveling with them to meet customers), find one that does.
And if you are a cofounder, whether technical or not, you are a business person first. If you aren't sharing your opinions on the best way to sell to your prospects you aren't doing your most important job as a founder.
I'd second this, I remember something that really struck a chord with me was Eric Ries saying, in a LeanConf Interview session that a founder does whatever is needed for a company to survive first and foremost, and the technical aspect is just the fact that you have more experience in that area.
And if you are a cofounder, whether technical or not, you are a business person first. If you aren't sharing your opinions on the best way to sell to your prospects you aren't doing your most important job as a founder.