Let's look at the pros and cons:
Pros:
High 120 base Atk Stat
Easily accessible
Passable Defenses
Only one weakness
Cons:
Shallow movepool
Outside of 120 Atk, stats aren't stellar
Can be mixed attacker, or specialize in either Sp. Atk or Atk with equal stats in each
110 base Spd
Wider movepool
One weakness
Terrible Defenses
Only 90 in each attacking stat
Previous Evolutions are hard to come by in the wild and will require grinding
So with those pros and cons in mind, I would probably do Luxray, but Raichu is still fine. If you are willing to wait, some other (better) Electric-types would be Electivire, Magnezone, and Rotom, which can all be found in the fourth area. Luckily though, Eevee can be found in the first area which can evolve into Jolteon. Hope I helped!