To sum it all up, if you have access to trading, Electivire is the best out of the three. It's got the great offensive stats of Luxray, but unlike Luxray, it isn't hindered by low speed or access to nearly no coverage. Magnezone and Electivire are probably your best bet for Electric types in BDSP, or you could just teach a strong Special Attacker Thunderbolt.
Pachirisu is probably the best out of all accessible Electric types though, nothing can compare in its might.