Steering shimmy when on brakes

[bonez]

My steering wheel shimmys when I first get on the brake, more pressure will make the shimmy go away.

I'm guessing I have a warped front rotor?

Is it ok to just cut them assuming they are nowhere near min spec? (if there is less than 50% ill just replace it) I found replacement OEM quality (Balos) vented front rotors for around 40$ shipped and cost to cut was around $10.

I just want to make sure that cutting them is a reliable fix and it wont warp in the near future. (logic tells me that if you have different thicknesses of metal itll be more prone to warp.. but apparently cutting is the accepted standard of how people get rid of shimmys??)

thanks