Very nice fixture! Seems David Lay is very clever when it comes to whipping up fluorescent fixtures!

He is!
How long (in inches) is the lamp?

F13T8 is 12"
I've got a few of those F13T8 lamps .. been thinking I might build myself a 2-lamp fixture for them sometime (it'd just have a boring instant-start electronic ballast though)

Maybe a 15w preheat choke would run them?

Nice fixture, I wonder if a PL 13 choke would work.

Now there's an idea; I never thought of that.
Or if it would fit you could stick a slimline ballast in for awesome EOL shows on dead lamps! But I think the 13w PL choke might just work then. Do they make 13w canister shaped starters (I'm guessing it would be a FS-13 then) or would you have to remove one from a dead PL?

The F13T8 should start fine with a FS-2. In fact every fluorescent under 22W normally works properly with FS-2 starters. There's a FS-5 for F4 to F8T5s but the FS-2 works fine with those as well. The 22W circline can also use the FS-25 which is made for F25T12 33" appliance lamp.

There's no FS-13 BTW xD

I didn't think there was such a thing...

Awesome fixture...gotta love preheat.

I agree...try walking into my room lit by all preheat CFLs in total darkness, and seeing the starters glow then they start blinking and shedding some light on the scene...VERY COOL!
Dieselducy, what color temp is this lamp?

This is a Cool white lamp, currently im burning the eiko lamp.