Letters of recommendation

[betch]

Anyone have trouble determining who to use for grad school letters of recommendation when the bulk of your credits are through testing? I don't have any professors who can say anything about me..
My thoughts were:
1. one from a professional in the field I am pursuing who knows me well
2. one from a private school dean who knows me well
3. one from my employer

Any suggestions or experiences out there?
Thanks much!