I have had to do this in London because I use a hosted BES service from Mailstreet in the UK. Hardest part was finding anyone in the O2 sales area who understood that I wanted to buy the Enterprise service, but did not have my own BES. Eventually went to a small CarPhone Warehouse (O2 reseller) called Ecocall who deal with lots of contractors like myself. Got an 8700g with the Enterprise level connection from O2. In the UK this is bundled as 'mobile groupworker' but usually only sold through to large corporate customers.