Here is a ropey triple T12 fitting I made with a cheap unbranded 18W T8 fitting, a Tridonic 18Wx3 ballast and a couple of cheap Hong Kong triple G13 holders.
It runs perfectly fine and is currently running 3 Homebase T12 20W 827 lamps.
The lighting is similar to a 200w incan which it is replacing with the expected changes being the lighting is much more diffused and a little more warm.