desk chat vs salesIQ

Trying to understand the difference between the two options and which is preferred and why. Our company switched to salesIQ and it is great for sales but not so much for support. I really want my chat to have the ability for the customer to come to our website and ask a question that first takes them to the appropriate list of KB articles. If this doesn't answer there question then we start a chat.

With salesIQ it is the opposite. We get a chat request, start the chat, the customer asks us a question and about 90% of the time we then we send them a link to a KB article that explains what they wanted to know. This cost us support resources and the customer time.

Related to this question then is. Can we use SalesIQ on product page chats and Desk Chat on Support page chats?

thanks to all of you knowledgeable users. I'm new enough to Zoho to need some guidance.

- jack