anyone have any experience creating a sign with letters of flame?

I'm thinking letters that are 3-5 feet tall, and burn with a steady orange-ish (blue-ish would be ok too, but far less cool) flame at night. Fuel source would preferably be propane.

I've thought about modifying gas grill burners to fit them into a trough of sorts, but I'm not sure how well the propane would spread over that sort of distance.

another option I've looked at would just be steel pipe bent to form the letters, with holes drilled every 1/2 inch to make small gas jets. Also not sure if the flame would spread enough with this...

Whatever the burners turn out to be, they'd probably be mounted in some sort of steel trough to try and dissipate the heat.

Oh, and this whole contraption will hopefully be a 10-12 feet off the ground, so people can walk under it. (I'm not sure if that makes it better or worse...)

any ideas?

Thanks!

-jeeves.
(who usually believes strongly in a policy of safety third, but sometimes lets it slip to 8th or 9th...)