Black, washable trousers for the-wide-of-hip pear - and not pricey!

[ShutUpLegs]

I am about to volunteer at a local hospital and have to wear a polo-shirt (provided) over black trousers (not provided).

I have worn no trousers other than jeans/M&S 5 pocket jeggings for the last 7 years and have no idea where to start. I also only have 1.5 child-free hours this Saturday in which to locate and purchase so I do not have the luxury of time to Try All The Trousers.

Can you help me narrow the field if you are a black-trouser-wearing pear?

Criteria:

1. Machine washable (they have to be washed between shifts)
2. Fit over big hips (I am between a 14 & 16, depending on levels of stretch)
3. Preferably not too flappy at the ankle - I have a bad habit of catching my foot in my trousers and plunging down stairs.
4. I think I instinctively prefer a woven to a jersey but that may impact on criteria one.

Do I just go to Next or M&S and then Try All The Trousers until I cry?

I have to alter trews quite a bit, or sew closed the pockets. And I always wear a belt. I won't buy trousers without belt loops anymore. Makes buying trousers a good bit easier.

Now why have I never thought of sewing the pockets up?
They always gape open, sewing them shut is such an easy fix [facepalm]

I hate those slanty pockets. They add unnecessary bulk (how polite am I). I always see them closed.