WHMCS and Stripe Integration

I need help integrating Stripe Subscriptions into my WHMCS (Version 7.x).

Requirements:
- Implement Stripe Subscriptions payment gateway
- Enable custom billing cycles

Ideal Skills and Experience:
- Strong experience with WHMCS, especially version 7.x
- Proficient in Stripe integration, specifically with subscriptions
- Experience with customizing billing cycles in payment systems