Hi There,
Please share your existing website which you want to make responsive.
I have done many similar projects and I have hands on experience in website designing, graphics design, html, css, responsive website design , twitter bootstrap.
Here I want to suggest you to use twitter bootstrap to make your website responsive Since it works with a central set of development code, BOOTSTRAP'S results are uniform across platforms. You’ll see the same thing on Internet Explorer, Chrome and Firefox.
I hope you would be interested discussing in detail.
Awaiting a positive response from your end.
Regards.
Amrita.