Unless your Accutron is Phased to the lower voltage 1.35V Accucell I would stick with the 1.55V 387 or 394. The bottom line is you "MUST" use a spacer with either of those batteries in order for the battery compartment to be safe(not short out) and have that battery/spacer installed properly. The Accucells mentioned above generally have a much lower battery life (my personal experience from past trial and error) and command a much higher price and are used mainly in 214's that can't operate properly with a 1.55 V battery of the 387/394. Although this general comment but not a 100% deal breaker, the Accucells are generally used for people that haven't had a watch serviced and phased to the higher 1.55V useing the 387 or 394 battery. Or the Accucells are used by a couple known repair agents that are either ill-informed or lazy to phase the watch to the higher 1.55V 387 or 394. 99% of 214 accutrons can be phased to run the 387/394 batteries just fine and that battery will not damage the circuity. I view the Accucell as a band-aid So you really need to keep a spare or two of the MUST have spacers and then later buy the much cheaper 387 without the spacer or the very commonly purchased 394 without spacer. I have nothing but 394's in all my 30+ accutrons. I install nothing else and they all run great. I have about 30+ spacers as spares so its really about buying a cost effective 394 battery when its time to refill my stock. You have spacers and you have a 387/394 battery, then you are set.
This is an in-depth look at batteries and phasing Q&A on the 214 movement. Phasing 214's and Batteries Tech Link