There are more ways to skin a cat than there are cats. I can think of several ways to do this, from several different vendors.
My suggestion would be to approach your vendor of choice (probably IBM in this case), and ask them to propose a solution. If that solution works for you, and is affordable, I'd run with it. If not, open up the bidding to at least two more vendors (and inform your vendor of choice, of course), then see what happens.
The biggest problem that I see is that when you are doing this kind of integration, there are many factors that come into play. Without considerable knowledge of your circumstances it would be easy to lead you astray and cost you an enormous amount of extra money or create a solution that was only part of what you need.