Emerald team help

I got emerald in the post today, and I wanted to know how you guys think I should finish this team (with all HM's)

So far ive got


Mudkip- water/ground moves: Surf, waterfall, dive, earthquake
Salamence- flying/dragon moves: fly, dragon claw, double edge, shadow claw
Gardevoir psychic Moves; thunder bolt, shadowball, psychic
Breloom grass/fighting moves: rock smash, sky uppercut, leech seed, leaf blade

I would like to have pokemon I can get relatively fast, (no higher then level 30), also i would prefer it if no types where repeated and each pokemon has 2 types (not necessary). also please tell me the move sets too, thanks in advance!

OK, Here's my review.

All of Mudkip's moves are resisted by Grass, so every Grass-type will have a field day against Mudkip. It's a shame that you can't replace HM moves, unless you're using him as an HM Slave (which in that regard I would've replaced Earthquake with Rock Smash), as I would've replaced the useless Waterfall and Dive with Ice Beam and Toxic. Ice Beam eliminates Grass types and Toxic hurts bulky walls.

Double-Edge is useless on Salamence, especially considering that an STAB Dragon Claw has the same base power, no recoil, and is not resisted by Rock or Ghost types.

Cresselia is not a problem, but keep in mind that these moves are resisted by Magneton and Shiftry. Becuase there's only three moves, I'd recommend Calm Mind for the fourth moveslot, as it boosts your special attacks whilst making it bulky on the special side too.

I'd never use Rock Smash on Breloom. Mach Punch is always the superior option as it has Priority and deals double damage.
Edit: Didn't realize that Rock Smash is an HM move as well. If you want Mudkip as an HM Slave I'd put Rock Smash in his movepool rather than in Breloom's. That way you can delete Rock Smash from Breloom's Mach Punch (which it learns by level 23).

I hope this helps!