Why not just add a link to your portfolio to DN sales platforms in your signature that go through an escrow process? If someone is interested in a name, they will message you as they know that's your domain and you can negotiate over NamePros.
Somewhat good idea, but another portfolio management system on top of tons of parking programs... on a forum? It doesn't make sense if you think about it.
Or, you could just create a for sales thread with multiple domains linking to a sales page, state that prices aren't written in stone for NamePros members and offers are acceptable. Update the OP of the thread when you add or remove a domain. Then it's 1 link in your signature to a NP thread.