Start with the ole standby McCormick Chili powder. And try using Red Kidney beans. They hold up better and add a great taste to the chili.
I used to use jalapeño peppers for the heat but everyone complained it was too mild.
So I now use one fresh Scotch Bonnet chili pepper with two toothpick holes punched in it and just drop into chili half way thru the cooking process. Adds a nice complete different flavor to the chili.
Now no one ever complains that the chili is not hot enough. :C
Scoville Heat units (SHU)
Habanero chili peppers are 260,000 SHU,
Scotch bonnet pepper is 445,000 SHU.
Not sure how hot this is?
As a reference, jalapeño peppers are only about 1000-4000 SHU.