Claydol's no worry either; it falls quickly to double surfs as well, or Surf + Razor Leaf. =P Really, it's Xatu you should be worried
slightly about, and an attack from the thing you used to wipe the floor with Winona will work. =P
HP - Whismur - Cave on Route 106
Attack - Carvanha - Route 119 (Super Rod)
Defense - Sandshrew/Skarmory - Route 113
Special Attack - Spinda - Route 113
Special Defense - Tentacool - Almost Anywhere you can surf
Speed - Zubat/Golbat - Cave of Origin
Look up to see how many EVs each give, and factor from there. =) Everywhere you can access has those Pokemon, though; Zubat are in almost any cave, after all. =P Also; remember, in Gen 3, the Phsyical/Special split hasn't happened... Is Bug type special, or physical?

4 Pokemon, so you can have two sets. 3 for Singles, 4 for Doubles, 6 for Triples, and also 6 for Rotations and Launcher battles, which follow the Triple battle rules. Also, that'd be problematic, unless you somehow had a friend willing to help remedy your Wi-Fi trouble. =/
W/W2 will be totally impossible for me UNLESS I get into a housing/job situation where I can remedy that problem (read: I get a job and move into campus housing).

Unless...say, have you ever tried to hook up a DS to a public library wi-fi? (Or unless MTM stumbles across a working DSi/3DS emulator that can connect to the online Nintendo features.

)
I did
not wipe the floor with Winona, I PP-stalled her.

A STAB Carvanha-Crunch should do the bird in, or alternatively my EV-trained and advantageously-Natured Cacturne can STAB Faint Attack it to kill it.
@ the EV-list: OK, that'll be good, I should be able to get some good training done with that.

Pin Missile is a Physical move in Gen III, but since both of Cacturne's STAB moves are Special in Gen III (the Grass-type Needle Arm and the Dark-type Faint Attack), a Special-oriented Cacturne will be great. For modern games, though Cacturne will be Physically-oriented, since all of its moves will then be Physical.
I should ask: should I bother with defensive EVs on Cacturne, or will I be better off investing in HP? I already know I'm going to be outsped no matter what I do, so there's no sense investing more than a few EVs in Speed.