Fox Labs has a very good reputation whenever the subject of OC spray (Oleoresin Capcasin) comes up on the various firearm discussion boards.
http://www.foxlabs.net/Products.html
If her primary concern is being cornered in a tight spot, you may want to look into the foam model. It's less likely to create a fog, or backsplatter that might incapacitate her in tight quarters.
Also, as to your wife's situation, she should make a journal, noting place, time, date, and the basics such as anything the guy says, in any further incidents she encounters. She should also do the same for the complaints she makes to the boss. If there's e-mail at work, even better, she should complain to the boss through that, and save hardcopys of her messages, and any response.
Doing that would make her the perfect client for any lawyer, should it come to that. Or, it might just be a kick in the u-know-where to the boss that she's serious, and he should be too.
If he threatens her with any disciplinary action or firing for keeping such documentation, or repeatedly bringing up the complaints, he's only digging himself deeper, sweetening the pot for any settlement she would eventually get.
Retaliation by an employer for complaining about sexual harrasment is an even bigger no-no than the harrasment itself in the eyes of the law.