Resizing to Specific Dimensions

[Apathetics]

Hi, guys!
I'm trying to resize well over several thousand images to certain dimensions for thumbnails, enhanced images, and etc. for my website.
I've tried using Photoshop's "fit to image" and "canvas" size to no avail.
For example, if a picture I'm resizing is around, let's say, 1500x1200 resolution, how would I change it to fit at a 660x880 resolution while keeping it in proportion?
It can't be a variable of anything X 880. It HAS to be an exact size of 660x880.
I thought about cropping the images, but since there is about several thousand...
Thank you for your time! .

[Paul MR]

As they are two different ratios one way would be to use Content-Aware Scale you can enter the exact pixels in the W and H fields using 880px and 660px

Another way would be to use fit image then alter the canvas size to the required size, this will retain propotions but give a border.

[Apathetics]

I've already tried using the second method, but the border makes the image look really awkward, especially for my shopping cart website.
As you suggested, I used the content-aware scale and setting the scale to 880px and 660px, but it came out looking extremely distorted.