You could always make your own, I have loads of different ones ranging in size from a giant 1 pint job made from a tin which once held Ye Old Oak Ham, (other brands are available) which I deliver on the end of a landing net handle, right down to match box sized ones made from the base of plastic bottles or aerosol caps. When I remember I paint them with matt black paint but tbh I don't think its necessary.
I normally attach the weight to the body of the dropper as per the Fred Crouch ones, I find it helps with the opening of them, particularly with the smaller models.
The best ones are made from pilchard tins, they are very light and if you overcast they will skip over the surface to allow you to drag them back to where you want them to fall, this allows for very accurate baiting.
My favourite of all is not the best but the first I ever used. It was given to me by an old friend now departed, it's made from a tea strainer, I've had it for about 20 years and it goes everywhere with me.