Either the NPL9 or 14 should work. The NLP20 is about 1.5" wider as well as being deeper, so if size is an issue, it may not work for you. The NLP14 is listed as a direct replacement for the Yuasa YTX20CH-BS though, so that's the one I'm going with. The Noco batteries and chargers get really good reviews and are about half the price of the Antigravity batteries while having similar features. The Antigravity ATX12 is the equivalent, goes for over $200, but is a 6Ah rather than 4Ah (NLP14) or 3Ah (NLP9).