My local tax office told me to go to TxDOT, that they have a list of bonding companies. That is a bunch of hooey- they specifically do NOT have a list. (It would be a conflict of interest: the state steering business to a private company.)
Speaking again with my tax office, they told me to go to my insurance company. My company doesn't write bonds, but referred me to one who would. They wouldn't.
Third try was a charm: the local tax office said (with a wink) they were NOT recommending a particular company to be, but "we get a lot of bonds in here from Insurance Office A and Insurance Office B." I went to the A office and got it uneventfully.
Bottom line: also consider searching out local convenient insurance offices.
Speaking from experience,
Bill