The Synapse in general could be a great boot, but you really need to go to a shop and try on as many boots as possible. Boots really are a personal choice and fit everyone different. The best boot regardless of price and other factors is the one that fits comfortably, has minimal heel lift and provides the support you are looking for.
Personally I use a Salomon F22 and love the quality and fit. The F22 has a narrow foot box so despite how I great and versatile I think it is, it wouldn't be the right fit for you.