This is a comprehensive list of routers that are compatible with Tomato firmware. The two active communities supporting continuing work on Tomato firmware are Tomato by Shibby and AdvancedTomato. Both are great and have passionate developers contributing to each mod.
I recently upgraded my router and I found it difficult to find a good router that was readily available, compatible with Tomato, and had the features I needed. I decided to make a list of all of the Tomato compatible routers, their features, and the firmwares they are compatible with. I thought this would be helpful for anyone looking for a Tomato router.
Many of these routers are very similar in features and many of the older versions are no longer available. Shibby supports a lot of routers! A word of caution, many of these routers have different hardware versions and some are not compatible with specific Tomato builds. Before you buy make sure you double-check the build compatibility!
I was interested in a recent mid-range router that had dual band coverage, a fast processor, and Gigabit LAN ports. A fast processor is handy when using the router for VPN tunneling, often the processor speed will be the bottleneck for traffic. I settled on the Asus RT-AC68U but a few routers will fit the bill.
I would also recommend the Linksys EA6900 and Netgear R6400.