PC ballast/socket & pin configurations

I've been shopping for a ballast for a retro PC install. I found a
couple good deals on Fulman Workhorse ballasts. In specific I'm
looking at the Workhorse 5 Long 120V/128W
(http://www.fulham.com/wh5.html).

One aquarium lighting site that lists this ballast specifies whether
each ballast is for square or straight pin sockets (it's not part of a
kit - bare ballast only.) However, the manufacturer's website and
other squarium lighting sites don't seem to specify types of socket
for ballasts.

So, my question is this: can any ballast be wired to use either type
of socket? Or are the manufacturer and other websites leaving out
critical information???

The bulb I need only comes in square pin (well, for the price I can
afford, which is $15 cheaper than anywhere else.) But the other site
I mentioned said the ballast only does straight pin! grrr...

Where's Patrick Timlin??? He used to answer all this lighting stuff
for me...

Thanks!

Kristen