While Raycore SIPs are an excellent choice, other reputable SIPs manufacturers include: 1. Kingspan TEK: Known for their high-quality, energy-efficient panels, Kingspan TEK offers a variety of SIPs products for various applications. 2. Premier SIPs: With a strong focus on sustainability, Premier SIPs provides a wide range of eco-friendly, high-performance panels. 3. Insulspan: Offering both EPS and GPS core panels, Insulspan is a popular choice for residential and commercial projects. The best structural insulated panels for your project will depend on factors such as budget, availability, and specific project requirements.