twofer,
you could go up with the cayenne. it would change your heat profile with very little change to your flavor profile.
one idea that i have been toying with is to add maybe one tablespoon of lime chipotle rub. it is made by A.C.Legg and i got a bag of it at the starke florida contest last december.
the other idea i was toying with was taking homebbq.com sweet orange habanero rub. that i would have to do outdoors since i would have to grind the same one tablespoon amount. don't know if you have ever ground dried habaneros before but if you haven't only do it outdoors and for gosh sakes never smell what you just ground. i learned that the hard way.
another way you could get your heat profile up would be to use one or two fresh red savina habanero peppers. this would change both the heat and the aroma profile since they smell so fruity when cut.
hope this gives you some idea on how to change it around and have fun doing it!!!!
glad you and your wife like the recipe and the canning can get into your blood!!!!
jack
ps. if you do make some changes let me know what you did and how you liked it. i'll do the same when i get around to making my next batch in a couple of weeks
pps. here's a down and dirty way to add heat. get some tabasco habanero sauce or even better would be marie sharps or sontava (both we can get at wally world here) and just measure some into what you have already made to get an idea of how hot you want to go.