NTPv3 stratum-1 with MD5 availability

We're reworking our current NTP infrastructure and are looking for
public NTP stratum-1 servers (we don't currently have the resources to
run our own stratum-1 at this time) that are willing to allow one of our
stratum-2's to get and distribute time from.

We'd like to use MD5 authentication and so far I've had limited success
in 1) just getting any response from nearby stratum-1's, but also 2)
finding public stratum-1's that will do MD5.

Before I start going down the list and bugging stratum-1 admins in other
regional areas on David Mill's public list, is there anyone who operates
or knows of a stratum-1 that will offer this service for us (and someone
or someplace I can marginally validate the trusthworthiness of :-).

Replies are probably best off-list unless you want to broadcast to the
world that you offer such a service.

Thanks in advance,