thats a good question I would start here with the dept of public safety
http://www.dmv.org/tx-texas/vehicle-registration.php
and ask what is required for inspection/registration.
the DMV is pretty easy going as far as tags and plates. mine is regestered
as a 1969 beetle also. but thats not the wright way to do it
you shuld probobly go for assembled vehicle if you can. that makes it easer to sell in the future but is a pretty good work out on the front end.
the two problem areas are insurance and inspection.
inspection is pretty straight forward lights blinkers
good solid roadworthy equipment
and insurance is limited to who you know in the buisness LOL
mine is regestered as a dune buggy but has limited restrictions as to its use
its with a company called
http://www.midwestclassicins.com/
they have both rails and buggys but are pretty selictive on who they cover
Ill do some research tonight and make a link/sticky on the forums