3rd Gen Only 1 strong pokemon.. stuck at elite 4 (LG)

So I was SO THRILLED with my chansey that its basically all I've used since I got it. Now I'm at the elite four and cant get further than two or at best three pokemon into Bruno's team, because all my pokemon suck besides Chansey who is a level 75 with Bolt/Beam, refresh and softboiled.

I'm training up a Kadabra with exp share (currently a level 36 or something) because I'm bored of the elite 4 and thinking of using psychic.

can anyone offer me tips on what other pokemon to train to get through this quickly?

most of my pokemon are around level 30, so it wouldnt be hard to catch a freakin level 5 and give it exp share, it'd be the same level in a few battles.

Perhaps a Water/Ice Pokemon would be good for Lance, or a Pokemon in general with an ice move. That was you can take down his Dragon Pokemon easier than if you don't have an Ice Pokemon/Attack. :]

Other than that, just pick some Pokemon that would help you with the elite four and give you a pretty balanced team, especially for your Rival afterwards. ^_^

blah

Well having a good strong hitmonee is always useful against anyone, just not Agetha. But go for Articuno, that will really help with them, especially since it comes at LVL 50. Other than that, maybe a strong ghost type.

Psychic works for Bruno. Flying also works, but be careful- most of his Pokemon carry Rock Tomb or something similar. An Ice-type move (Ice Beam or the like) will be very useful in dealing with Lance, so a Pokemon that can learn an Ice-type move will be helpful (also on Bruno's pair of Onix.) A generally balanced team can take down your rival pretty easily.

Go and catch the legendary birds maybe? Aren't they all like level 40 or 50 when you catch them?