Behind that link you put in, I couldn't see any mention of DDNS. Domain registration and web hosting, yes, but not DDNS.
I haven't tried this, or investigated the DDNS services out there, but there's a more basic problem: the terms of service for your ISP might not permit you to run any servers on home broadband - better check. You could chance it, then find that the ports you need are blocked, e.g. SMTP port 25, which you'd need to send mail. I looked at Talk Talk's website, but they don't mention servers specifically, only P2P.