I use these amongst others @Kingtut , the 4 way can be made into a 2 way by removing 2 of the bulbs. The 2 way has to have both bulbs running, the 4 way can have 2 or 4 running, so 55 x 2 =110 w or 55 x 4 = 220 w
http://www.hydroponics.co.uk/starlite-propagation-canopy.html#.WeB9bf6WzIU
I normally sit 1 prop under it long ways with 20-30 clones in chequer’s board style, or place 2 props under it side by side and turn them width ways.
Hope this helps 
Alternatively look up the SOL strips thread, diy veg lights, theres a link in herbies garden thread to it some where.