I had the same problem finding a comfy position after moving from drops to straight bars. Butterfly bars may provide an answer as they do offer a variety of hand positions as well as accomodating mountain bike type brake levers which are powerful and easy to operate. I don't like them myself but others swear by them. After years riding on the hoods it took ages for me to come up with a position on straight bars which duplicated this position. For me the answer was to cut down the bars to my shoulder width then to fit them with bar-ends in a more or less horizontal position. I wanted the upward curving shape of the hoods and unforunately I couldn't find bar-ends which gave me this. I ended up making my own bar-ends from the curved section of an old pair of drop bars and screwing and aralditing them to a pair of clamps taken from another pair of bar -ends. I then padded and taped these to give a comfortable platform for my hands and have ended up even more comfortable than on my drops.
I would imagine that WIGGLE would have these on their website and if you Google that or "www.sjscycles.com" you should be able to have a look at a pair of butterfly bars. Good luck!