You can checkout Shopcast theme at https://boostheme.com/category/best-shopify-themes/product/shopcast-high-performance-multipurpose-sh... . It loads very fast. These are performance testing results on Google Pagespeed Insights https://developers.google.com/speed/pagespeed/insights/?hl=en&url=https%3A%2F%2Fbt-shopcast-1.myshop... , GTMetrix https://gtmetrix.com/reports/bt-shopcast-1.myshopify.com/nO51Kl0J , and Pingdom https://tools.pingdom.com/#5b98d188f5000000 . In addition, you will save lots of costs for Shopify apps because this theme has the features like Shopify apps such as frequently products bought together, free shipping notification, collection tree in collection filter block on the collection page, and tons of strong features. Hope you will like this theme!