As an experienced Full-Stack Developer, specifically in Laravel and PHP, I have successfully integrated numerous payment gateways varying from Paypal and Stripe to Razorpay and Paytm. I've also been proficient with working on clean codes, using APIs effectively and ensuring top-tier user experience for over the last 8 years. Thus, I believe I am the right person to handle your project of integrating the payment method from Architect HTML site builder software with Paytr.
Additionally, I have a comprehensive understanding of Omnipay framework that you mentioned as well. This will prove to be a valuable asset in swiftly replacing the existing Paypal payment method with the Paytr's integration.
In addition, my affinity for creating highly scalable and easily maintainable applications aligns perfectly with your needs as this change will not only be implemented but also secured for any future updates or maintenance.
To sum it up, my extensive skill-set and experience in web development make me confident to undertake this project efficiently. I'll work diligently, paying attention to every detail, ensuring that the integration of Paytr into your system is seamless and error-free. Thank you for considering me for your project.