Replacement material for a lead roof?

We need to find a replacement for our lead summerhouse roof. The first time the thieves only stole the flashing from the ribs of the roof. We replaced it with 'Perform'; a product the manufacturers of the summerhouse suggested. We didn't particularly like the look of it as it looks like gaffer tape and was more expensive than the lead! However, the night the roof was repaired and uncovered the thieves were back for the lead they didn't get the first time. Nightmare! We now don't really know what to do. The roof is scooped so ordinary tiles won't work. Is there anything out there that could replace our lovely lead roof and look as beautiful? Help appreciated.