PN vs BT

[#1]

I need to recommend a broadband supplier to one of my customers for usage to connect to the AT & T MPLS network using a NetGate router.
Current options are either PN or BT, and the customer wishes to pay via invoice. I'm prepared to do the invoicing and pay for their line with my Credit Card so that's not a problem, however I need to provide justification for using PN instead of BT. As they have had very little downtime with the current provider - Pipex I need a guaranteed quality of service.
Suggestions anyone?

[#2]

Thanks for your reply, any idea what real world VPN speeds I can expect with onward connection to Germany?
cp:blue There is no need to Quote the full preceding post. mod:end