dew dropI would second the acrylic recommendation. That way you can line up your letters better. I don't have a specific brand recommendation for acrylic stamps. I think most of them are good and would go with whatever font you like best. As for ink, though, I would strongly recommend versamagic or brilliance dew drops to use with your new acrylic stamps. Enjoy!
there are a couple different types of alphabet stamps but I would like to tell you about two types.
The first type are clear letters that you arrange on a piece of clear acrylic (but you can use a CD jewel case in a pinch). These stamps are great when you are doing a title and you want to be real percise about your lettering.
Then there is another type of alphabet stamp where each letter is mounted on a little square sided stick. (The entire alphabet comes in a little box.) These stamps are GREAT for quick, spontanious stamping like for pages & cards where it won’t kill you if the letters aren’t perfectly spaced and lined up. These stamps (on the little sticks), while they seem old fashion are A LOT easier to use and I find myself grabbing for them all the time. And because this type (on the little sticks) are not considered trendy you can get them dirt cheap (either by using a coupon or by buying used).
ps just to clarify "easier"
There is some effort involved in peeling the letters off their clear storage backing, lining the letters up on the acrylic (and if you don't have enough of a letter you have to leave spaces or break out the words), and returning the stamps to their proper spot on the backing.