Per the DH Terms of Service, "Servers are shared with other customers, and as such IRC-related activities or severely CPU intensive CGI scripts (e.g. chat scripts, proxy scripts, scripts which have bugs causing them to not close properly after being run) are not encouraged."
That said, there are numerous chat scrips available that you could probably install on your site (check out http://www.hotscripts.com), but you will need to find one that is "lightweight" enough not to be killed by DH.
Alternately, you could make use of DH's Jabber services, available via the webpanel.
BTW, Why are many of the products on your site listed with selling prices above the MSRP, and why are none of the "credentials" or "certifications" across the bottom of your site (truste, BBB, etc.) linked to the actual certifications as required by the TOS of those organizations? Does your site actually have these certifications?