The spiral CF in BL or BL-B are pretty pricey, from what I've seen, with low output relative to the larger sizes of tubular fluorescent. Much simpler to build the unit, but you'll probably wind up spending about the same unless the bulb shape lets you use a much smaller unit and fewer bulbs. I've been thinking about using an array of 6 to give an 8x12 inch printing area, but that'd still be something like $100 to build the unit (counting lumber, sheet metal, wire, and sockets).