looking for a cast iron waffle maker
don't own these, but here are some links you may find useful:
As Paul said, you can find the antique cast iron waffle irons on eBay and etc.
There are electric version of cast iron waffle makers, but those are fairly expensive.
FWIW, I REALLY like the Rome Waffle Iron.
Do realize your first efforts will probably be a disaster, so plan on two or three trial batches before doing a family breakfast. (A good strategy would be to use up extra pancake batter -- spray hot irons liberally with PAM. Expect at least one episode of the irons getting "glued" together or with batter that needs to be chiseled out. Waffle batters are similar to pancake batter, but richer -- more egg and oil).
Once the irons are seasoned and you get the temp's figured out, the results are amazing. Consider spending a few more bucks and getting the "chuck wagon" model that has wood handles -- the iron handles on the basic model get extremely hot..
You can get Rome waffle irons at sporting goods places (look in the camp cookware section where they have the pie irons. Buy a pie iron while you're at it -- those are yummy!)