While Thunder is more powerful, it has a shockingly low accuracy rate, making it a very risky move to use in battle. TM41 gives you Thunderpunch, which could be a good alternative, though it only has 75 power as opposed to Thunderbolt's 95.
Maybe Rock Slide? You can get the Rock Slide TM in RBY, so just trade it over.
Or you could use a Thunder/Ice punch combination. Thunderpunch for water types and Ice punch for Ground types. Both will help with Normal/Flying types too, which your other moves can't touch.
Psychical Sweeper:
Rock Slide
Earthquake
Shadow Ball
Return?
Mixed Sweeper:
Earthquake
Shadow Ball
Thunderpunch
Ice Punch
Both should be almost as good as the set you had in mind. IMO, the mixed set is more fun.