Enhancing English to Punjabi Transliteration

I'm seeking a professional to refine the English to Punjabi transliteration system on my Shopify website. Currently, the transliterations are often incorrect, and the system does not convert natural English input accurately. The ideal candidate will integrate the Google Input Tools API to improve this system, however, alternative solutions may be considered if they can offer a better service.

Key Requirements:
- Natural English text input support: Users should be able to input regular English text and have it accurately converted to Gurmukhi.
- Accurate Punjabi (Gurmukhi) output: The transliterations need to be precise, eliminating the need for users to type in specific Gurmukhi-style English fonts.
- Real-time transliteration: The system should provide instant transliteration as users type.
- Support for common English spelling variations: The system should be able to recognize and properly transliterate common spelling variations.

Deliverables:
- Fully documented source code
- Comprehensive implementation guide
- Detailed testing documentation
- API documentation (if applicable)

Required Skills:
- Experience with transliteration systems
- Proficient knowledge of Punjabi (Gurmukhi) script
- Understanding of Unicode and character encoding
- Background in language processing