R/S/E Battle Tower Suggestions?

I'm trying to get over 50 straight wins in the battle tower, and keep losing due to the fact that I only really have one good level 50 pokemon, Latios. I'm not really sure what else would be good. I was going to try a sporeing breloom, but I forgot that you can't use higher than level 50 pokemon.

Right now I have level 50 latios, 50 Dusclops, 50 Claydol

Latios + Lum Berry
Luster Purge
Surf
Recover
Dragon Dance
Only problem is DD is kinda wasted on a special sweeper.

Dusclops + Persim Berry (Very limited item selection. Very.)
Curse
Will o Wisp
Confuse Ray
Shadow Punch
He's actually done fairly decent as long as Will o Wisp doesn't miss like 4 times in a row (that fucked me up at battle 35)

Cladol + White Herb
Cosmic Power
AncientPower
Psybeam
Sandstorm
He kinda stinks but can still take out anyone in the early levels with maxing out defense while sandstorm is going.

Right now your team is really weak against ice and REALLY weak against dark. I'd suggest replacing claydol with something like thick fat snorlax, which resists ice and doesn't add to your dark weakness. A standard curselax should do very well in the BT.

Your dusclops really isn't very good, either--will-o-wisp is useful, but curse is going to come back and bite you, and confuse ray is generally pretty chancy. If you wanted to keep dusclops, I would recommend keeping will-o-wisp, replacing shadow punch with night shade for guaranteed damage, pain split or rest (probably pain split) over curse, and either focus punch or seismic toss in the last slot. Leftovers is probably the best for this guy, especially as curselax is okay with chesto berry. However, dusclops doesn't really do a lot for this team.

For latios, I would suggest ditching DD, luster purge, and surf, and instead opting for something like psychic/ice beam/thunderbolt. Alternatively, you could replace DD with calm mind.

This team is overall pretty slow and doesn't have the best type coverage. However, I'm not sure how much you want to rip it apart and start afresh, so those are my suggestions to start with.

My main problem is severe lack of decent Pokemon and TMs, for example I lack an Ice Beam and Thunderbolt for Latios.

Dusclops could actually be done, since it's mostly heart scales required, but I'm wondering why Focus Punch would be good..? Since they're not going to have a chance to miss him unless they're fighting/normal where it wouldn't matter as much.

How would I get a snorlax in Sapphire? I'm nowhere near beating the elite four in FireRed, and there's no GTS.

I was actually considering a breloom as a physical sweeper, because I've got level 42 one that's been EV'd for speed and attack, but I don't know how great he would be.

Sorry, forgot there's no switching in BT. That makes focus punch mostly useless, yes. I wasn't aware that you didn't have access to anything besides the Hoenn dex.

Breloom's a good pokémon, but it doesn't help your ice weakness at all. I would put it in over claydol. You say it's already EV'd--what's its moveset? Without substitute breloom loses some viability, although spore is still good.

I migrated breloom because she learns spore at level 54, and this is a level 50 battle I'm doing because I never get around to training them high enough for 100. Heh.

I could get a Gorebyss as an ice resistor and water sweeper, replace Surf on Latios with something else perhaps. He could go over Claydol.