WHMCS Theme Integration

Description

We are a radio streaming platform who currently use WHMCS for billing. We have our own website theme that integrates with WHMCS as a standalone WHMCS theme. We are currently using WHMCS 8.1.3 and are due to upgrade our WHMCS installation to 8.11 - we need someone to take our current theme, upgrade it to the sufficient standards for v8.11 and fix any lingering design bugs.
The candidate must be well versed in WHMCS designs, especially with the latest 8.11 general release. They should have good knowledge of PHP, CSS and WHMCS syntax.
Applicants - please include links to previous WHMCS theme integrations you have completed, where possible.