Using Compaq's MA8000/ESA12000 with the HSG80 in a redundant cluster environment might be a good thing. But, before you start telling the customer too much, you should look at his needs very thoroughly.
If you use securepath together with an HSG80 controller pair, every server connected to this solution should have securepath and dual HBAs. This makes the investment very expensive because most of the customers would like to connect many resources to this solution. They'd also like to be able to share this storage cabinet among several servers and to use different levels of availability.
It's not possible with this solution. The reason for this is that when you use securepath the HSG80s are load-balancing. Compaq's advice is to buy another pair of controllers. This seems to be very expensive disk usage, don't you think?