3rd Gen Third Party Member

Ok. I'm currently taking a challenge that made friend made and it calls for me to use a Gardevoir in the three party team. I have my Ralts right now. But I can't decide on the Third member of my team. I THINK I will go with Skarmory as the second, but it's either that or Pelipper. I'm playing Ruby. If anyone can help me out please let me know.

I recommend skarmory over pelliper, and perhaps a wailord? A flygon if you want something more powerful. Cacturne for another option.

Nyaa! Swampert!

I trained up a two-Pokemon team of Gardevoir and Swampert and absolutely cruised through the game. xDD