Integrate Strategy Online Games into Script

I'm looking for a skilled developer to incorporate strategy online games into my existing script. The games should feature:

- Multiplayer mode
- AI opponents
- Leaderboards

Additionally, I want to enhance the gaming experience with:

- In-game purchases
- Chat functionality
- Customizable avatars

Ideal skills and experience should include:

- Game development expertise
- Experience with multiplayer game integration
- Familiarity with implementing in-game purchases and chat systems
- Ability to create customizable avatars

Please provide examples of similar work done and a rough timeline for completion.