Looking for a stereo mic for pd150. Which one should I get?

What will you be doing with it? If you provide a bit more information, it would be easier to answer your question.

Neither one are stereo.

The 300 is all-plastic and is difficult to fit for wind socks and the like. Also it has a shoe mount, not the more normal mount of a pro microphone (which is to say, they have none built-in).

The 66 sounds better and looks more professional. It also costs about $200 more.

I agree. One shop in town here even stopped selling the ME300 because they break too easily. The sound is also superb with the ME66/K6. There's a great mic test somewhere, maybe at Beales Corner, if I find it I'll post the link. In the test, many mics where tested, and the ME66 and ME67 came out on top. (The ME67 is very long, and also uses the K6).

(For the VX2000, you may want to consider getting a Beachtec DXA-4.)

The K6/ME66 is worth the extra coin. I tried to be cheap and all I wound up doing was wasting my time. I tried the MKE300 and discarded it immediately. I tried to be cheap and bought the AT835b. I took it back 2 days later, sobbing as I paid the difference (in Canada the AT is $380 and the K6/ME66 is $770).

I have never regretted that decision.

theres only one way to go the me-66, you might also try the mce-87 by beyerdynamic is good also...if youre going to spend the cash bite the bullet and get the k6/me66 mic....you also might check ebay for a sony ecm 672..