I live in Argentina and I manage to play with most GAFfers with bearable amounts of lag, so I bet you should be able to play against west coast players without any issues. I do use a wired LAN adapter, though, but I think the thing that make me lag a lot less was when I switched my internet connection to 12 Mbit/s down/1.2 Mbit/s up, since I'm now able to play against Karsticles fine even though the game lagged like hell when we had played a long time ago.
I think most of us SmashGAF regulars play the game competitively, or at the very least not at completely casual level. There're lots of players in here that are quite good with their mains, such as Snacks' Greninja, Karsticles' Bowser/Mewtwo, Out_Of_Ammo's Dedede, Wyndstryker's Zelda, Oidisco's Marth/Zelda/ZSS, Puruzi's Lucas (and many others), Shamrock7r's Ness/Lucas, Namikaze's Luigi, Tipster's Megaman and many, many others.
The fact that we play a wide variety of characters is awesome for getting some valuable match-up experience, and I think the skill gap among most of us isn't large enough that one of us is completely hopeless against the rest, so we keep improving and trying to one-up each other constantly.