twosblind,
i dont personally know any seaplane operators. i will try and point you in the right direction. i fly into KDWH (David Wayne Hooks) airport on the north side of houston every once in a while. they have a seaplane landing area at the field, i would think there may some operators there.
here is a link to the airport's website.....
new

maybe the airport manager would know of any seaplanes based there..

hope this helps.

Fly Safe!