Need help with my Pokemon team!!

Hey everyone,
I am replaying Pokemon Emerald because it is my all time favorite and I am trying out a new team. I do not want to have any legendaries because every time I have used one, they are OP. Oh hey! It's a LEGENDARY, but it gets boring when you use them. So far I have 5 of the 6 Pokemon for my final team:
Swampert
Gardevoir
Aggron
Shiftry
Salamence
(wasn't sure if I should use a fire type or electric type)
Any and ALL suggestions will help. Even comments about my team or how to improve them. I was using Altaria instead of Salamence but I like the way he looks and how much stronger he is.

I will suggest you to go with fire type (i always choose fire over electric or any other type :D). Dont ask me which fire pokemon to use because i dont remember where you can get any good fire pokemon in this version.

For Swampert the moves could be Surf, Earthquake, Ice Beam & (Endeavor??)
Don't think Ice Beam can remove its Grass Type weakness, it is to destroy Drake's Dragon type Pokemons.

Gardevoir should know... Hypnosis, Dream Eater, Psychic & Shadow Ball (or any stat changing move like Calm Mind)

I don't have much experience with the other three.

I hope it helps :)

Swampert
-Earthquake
-Surf
-Ice Beam
-Toxic/Rest

Gardevoir
-Psychic
-Thunderbolt
-Calm Mind
-*filler* (choose something you like)

Aggron
-Iron Tail
-Rock Slide
-Earthquake
-Protect/Substitute/Dynamicpunch

Shiftry (Bad Pokemon, low stats etc)
-Sunny Day
-Solarbeam
-Brick Break
-Shadow Ball/Faint Attack

Salamence
-Dragon Claw
-Rock Slide/Brick Break
-Earthquake
-Fire Blast

There aren't many good fire types in the game, Camerupt would be alright I guess.

Camerupt
-Earthquake
-Rock Slide
-Fire Blast/Flamethrower
-Eruption/Explosion

For Gardevoir a pretty good moveset would be Psychic/Thunderbolt (or Shock Wave)/Calm Mind and maybe something like Hypnosis (legendary catching, etc.) or Thief (if you want to steal some items). Shadow Ball is physical in gen 3, so it won't do you any good on it.

Swampert should probably run something like Surf/Earthquake plus something like Brick Break or Return or maybe Ice Beam. The main issue is just TMs not being usable more than once, so you won't be getting an optimal moveset for all your Pokemon.

I'd say that in terms of typing you could either put in a Fire type (like Camerupt) or a Fighting type (Breloom or Hariyama come to mind). Just keep in mind that Breloom has a terrible Special Attack, so its Grass attacks won't do much.

You also might wanna switch some things around for the HMs you need, because as it looks now, your Swampert's probably ending up as some sort of HM slave, because it's the only one capable of learning Dive and Waterfall.

If your Gardevoir has Thunderbolt, go with a fire type. If not, go Electric. The reason I say that is because Wallace is a Water User and the more counters you have to the champ, the better. I would suggest getting a fire type anyway for the final battle against Steven in Meteor Falls.

Fire Type- Torkoal- Flamethrower/ Body Slam/ Curse/ Toxic
Electric Type- Manectric- Thunderbolt/ Bite/ Iron Tail/ Double Team or Thunder Wave