WHMCS PayU Integration

I need a WHMCS module for integrating the PayU payment gateway. The integration should support both production and sandbox environments, and must handle multiple currencies.

Key Requirements:
- Support for both recurring and one-time payments.
- Refund processing capabilities.
- Multi-currency support.
- Integration with both production and sandbox environments.

Ideal Skills & Experience:
- Experience with WHMCS and payment gateway integrations.
- Familiarity with PayU and its API.
- Strong background in handling multi-currency transactions.
- Knowledge of both production and sandbox environments in payment integrations.

Please provide your experience and approach.