Hello . .
First, you don't need additional plugin to track user activities such as from where they came, what they visit. There are Google Analytics that you could use freely for these. It's free and I am ready to setup it . .
And for main requirements. I noted 2 points with the comments and questions to concluse my understanding about it
1. "Users can requests as many quotes as they want"
- Q: Are you not having problem a same user send duplicate requests ?
- C: A spammer could have spam the request form and it would took heavy processes for the server
2. "system will email it to them after calculating price based on quantity and other features"
- Q: Do you provide how the request form looks like - for quantity input, features input, etc ?
- C: There is a premium plugin that able to do these requirements. In fact, it would be more proven, easier, and faster. With additional extend/customization, the plugin would fit your requirement perfectly. And you could add many quotes form without limit. What are you think about this ?
I am document oriented WordPress developer. 3 years experiences in plugins development and customizations. I follow the best pratices of WordPress codex when doing my job
For consideration, please take a moment to visit my profile page. There are reviews and portfolio could be considered here
Thank you and regards,
Shelingholmes