Can I get these Pokemons before the gym battle?

Question

In White, I was planning on getting archen or dwebble before fighting Burgh. but there was a man at route 4 who stops me and says that I need to defeat burgh before I can pass. Does this mean I could not get either?

If no, can you suggest any Pokemon to help me defeat burgh?

I only have two Pokemons:
Servine
Simipour

(i know I suck T_T. I am actually re-playing the game so I could try using different Pokemons)

Comments

and thanks for all the help :)

---

-Use Simipour to deal with Dweblle with a Water move; look out for Sturdy, and Burgh usually likes to use a Super Potion on it so Sturdy will activate again.
-Get a Pidove and evolve it into a Tranquill, and it can take down Whirlipede and Leavanny with a flying move.

Answer 1

I won't include trading because that doesn't seem to be what you mean.

Archen: Sorry, you have to have access to Desert Resort on Route 4 to get one.

Dwebble: Sorry, you can't get Dwebble either. You have to catch it at either Desert Resort or Route 18, both of which you can't get to at that stage.