Flashers:
Vexilar
Marcum
Hummingbird
I personally own the vexilar FL-18, But have used or been with people who have used the other ones. Don’t let anybody tell you that one brand is superior to the other. It goes back to the Ford, Chevy, Dodge argument. They will all accomplish the same objective and do it well depending on how you take care of it.
The pricier models are digital, so the screen is easier to read and much more pleasant to look at. However it’s not necessary for the money, only a luxury of sorts. One feature that I would recommend which my FL-18 has, is the ability to zoom in on the bottom 6 feet. This makes it very nice when you were after perch or other fish that hover near the bottom.
Seriously you can’t go wrong with any of those brands! IMO, a flasher is essential, so you are definitely on the right track.