i haven't had a bad experience with hopar too. there is one fixture for 2 feet that comes with 4 reflectors for 4 tubes with build in timers the shop infront of ahbeng used to carry them for about 13 red notes
otherwise you could always mod your set. the fixture is just a container. all that matters is the ballast, wires, and perhaps the stock endcaps if they're reliable. individual reflectors can be bought from many lfs