Hmm, your Drifblim looks like a good option as it can learn fly and it's attack, sp.attack and hp are very good but its defense probably lets it down a little but not by much. Blaziken is one of those pokemon with high attack and speed but low hp and defense. I had a level 100 and its hp was around 290 or so (cant really remember). Tyranitar is a really good pokemon to have actually, it's got high stats in lots of areas if it gets all EV and stuff. Galvantula's speed is the best stat is has as it lacks on defense. Hp and attack is good though. I like Kingdra the most because it's got amazing stats and it's type is dragon (i have a thing for dragons). Excadrill is good for attack but reeally weak against water.
One thing you might want to consider is that you don't have a grass type. As galvantula is bug and electric it can pretty much only learn energy ball (i think) so when you're up against a water pokemon and Galvantula has fainted, because it's also electricity (grass and electricity super-effective against water) you might not have a pokemon which has a super-effective move against water. I'm just saying it might be inconvenient for you.
Hope that helped :?