Pre-Dervish Weapons

[Jthw]

A few days ago I started building a backup character for an irl campaign and because we have a bard that is going the obvious route of dragon fire inspiration I decided to go with a two weapon fighter build. After looking through the usual TWF classes I found dervish, remembered what it was instantly, and set my mind on it.
Here is where the problem comes in, we arn't level 6 yet and I want to, what weapon am I supposed to use before being an actual dervish? I would go scimitar/some light weapon but scimitar can't be finessed.
So I guess my question boils down to this: What is a good one handed slashing weapon that can be finessed. If none what is my best option.
The current option that I am leaning to is asking the DM nicely if I can be a dervish in training and have just one scimitar in my main hand and be able to finesse it, maybe taking a minor flaw to trade off or something.

Reason it needs to be slashing: dervish prerequisite and i don't want to burn a feat.
Reason it needs to be finessed: MAD.
Reason it has to be one handed: TWF.

Any suggestions appriciated. As of typing this I am about to go to sleep so I will look through the helpful replies in the morning.

[BowStreetRunner]

Just go with a pair of kukris early on - they are the poor-man's scimitars. Sure, they do on average 1 point less damage, but otherwise they should be perfect until you get your scimitars.