Great answers from both. Thank you guys.
On the side where the upstream ISP offers a BH service, it's all good. I just create the peering (which is all good) and then provide the /32 destination prefix with the "discard" statement to the upsteam ISP and also ensure that the originating ttraffic is sent to a 5k queue so that the bandwidth is limited and we can examine the packets. So, a double stop there.
I have e-mailed our account manager at the other upstream ISP to let them know that we want this service offered as well.
Obviously, written policies will have to be put in place for the monitoring of this traffic as the destination prefix is blocked which will also stop legitimate traffic to our customer. It's a little difficult to get source IPs if it is a DDoS attack we are eliminating.
Thanks again for your help.
Both of the answers are accepted solutions but I can only accept one as "solution", so, it's down to a flip of a coin.... 🙂