You will be much happier with the flourescent tube. The 40w bulbs throw out too much light and not enough UV.
The hand held, battery operated can be found at coin shows and shops for about the price of a UV tube for the larger lamps. I think the last one was $15.00 and they work just fine.
For pictures I have two 10w lights (unless they are 15w as you wrote) and I place one on either side of the chip(s).
I bought one at American Scientific, I think it ran $29.00, the other was $3 at a rummage sale!

But once again the little battery operated works fine and is easy to use or carry around.