Best amp for 6 ohms speakers

You ahve not specified the speakers nor the budget. So someone might recommend a top of the line Pass.

I use Parasound A21 with my 6ohms Quad. It is more than sufficient with a Passive TVC.

Some amps overheat if the load falls below 4 ohms...you should
check the amp ratings first.

I'm using Episode 700 monitor speakers rated at 130 watts RMS, 325 watts peak. I'm looking for an amp at $199 - $299 that's capable of driving them.

Those speakers are 89db sensitive so they should be pretty easy to drive. Are you looking for a power amp or integrated amp?

In that price range, a used Hafler is probably the best
sounding bet. Any of them can drive a 2 ohm load, all day
long, at rated power. Having the power supply caps replaced,
on the older ones, would be a good idea. Type, "eBay Hafler
power amp" in your searchbar. This site won't handle the
whole url, for a link. Another nice thing about the Haflers;
they are a piece of cake to upgrade/tweak, should you get the
urge later.