Depends a lot on where you live. Zone 5 New Mexico gives you a lot of choices. Zone 5 New York will really limit your options because of the wet winters. Would you be interested in "cactus-y" things like Agaves, Sedums, Sempervivums, and Yuccas?

There are a few non-Opuntia ones that would be good choices for wet spots, but you'll probably need to get them from a specialist. Look for Echinocereus triglochidiatus, E. viridiflorus, E. reichenbachii, all come in a bunch of varieties so you might find them under different names. Also the extremely tough Escobaria vivipara and Escobaria missouriensis.

For preparing your soil, simply pile on as much grit as you can get your hands on. More grit than soil would be a good idea if you are on the wet side of the country. There are lots of very hardy cacti, but very few that can stand being in wet soil when it is cold.

i live in indiana, the winters here can be pretty wet if we get a lot of snow. the area i am using is approx 2 1/2 feet by 5 feet and is in a raised bed with wood enclosing it like a box. would just adding lots of sand to the soil work? i thought about adding sand and putting pea gravel on top to be a sort of decorative mulch. prickly pear grows very well here so i know some cacti or succulents will work, just dont want a big investment in plants that will die. the plants you listed-is there a particular mail order source i can get them from?

You could have a browse as Mesa Garden. They mark their plants with a hardiness code which will be helpful to you and probably have the widest selection out there. And also look at Miles 2 Go for excellent quality plants.

I should probably comment on the soil too. Don't bother with the sand, that's not going to give you good enough drainage in your location. Even pure sand might not be good enough. Mix in gravel, loads of it. Make sure your raised bed actually drains from the bottom and doesn't fill up like a giant pot. Put holes in the sides if necessary.

Since your location is decidedly borderline for most cacti, don't go mad the first year. Start with the hardiest, if they die then you might have to stick with the prickly pears. If they live then you could try a few more.

thank you for the info about sand, i would have used it if i had not known. i will add a lot of gravel. right now the bed is a little low on soil so this is the perfect opportunity to add gravel. is there any certain type of size of grave i should use. i am not familiar with adding this type of ammendment, i am usually trying to add organic matter. thanks for you help.