If you have WPW and any high risk finding then you should have your pathway ablated. The external ICDs are for people who develop VT/VF usually following a heart attack. It can also occur folowing an episode of AF with WPW, and so they could be beneficial in your case. However, the best treatment is almost certainly EPS and an ablation procedure.
Those should be fine, although WPW rarely causes cardiac arrest, if you going into afib or some other SVT those AEDs will not work. To my knowledge it is drugs which are dangerous in WPW like adenosine and you may want to wear a braclet saying you have WPW just in case.