Can anyone recomend a large growing species of bamboo for zone 6a
(Louisville Kentucky). Would like to plant some along a length of fence
line. Also, is growing bamboo from seed feasible and practical
(germination
rate/growth rate)?

That's an easy one -- Arundinaria Gigantea. Bear in mind, bamboo spreads
pretty good (some are REALLY fast) so you'd better put in a rhizome barrier
around whatever you plant or you might be looking across to your neighbor in
a court room.

As for growing from seed -- sure, it's feasible but it's almost impossible
to find the seed. Bamboos typically flower once every 50-100 years. A
bunch have just recently flowered but most seed is being closely held (much
more profitable that way) and the seed does not remain viable for very long.
Better bet is to just buy the plants and go from there.

Burton's Bamboo is right up in Middletown, Ohio, a few hours drive from you,
and I think they ship as well. They're a good resource. Last I checked,
they also offer tours of their facility and groves as well. If anyone would
know what varieties would do best in the area it would be them.

James