the entire chip surface is available for wire bond set up. I had
         mine done by NMRC in Ireland, but you may be able to get somewhere
         a bit more local. From memory the cost was 900 Pound for the diced
         wafer. Expensive per chip, but you get a lot of bonding
         opertunities per die. The only thing you won't be able to do with
         this approach is check bond placement accuracy as there are no pad
         surrounds to reference against. I can give you a contact number
         for NMRC if you like. They are a university based electronics
         research centre in Cork.

         hope this helps,
         Jeremy Drake
         Design to Distribution Ltd
         Stoke on Trent
         England