Almost any *trumpet* shaped red flower might do.
Over time, I did some experimenting with going to a garden center, taking along a little black light [works better on overcast day]; shine the black light on the red blossoms of various flowers and what *you* see will be close to what a hummie sees ...as they are sensitive to a long-wavelength.
There is a lot of reading matter on the subject out there. :)
https://fieldguidetohummingbirds.wordpress.com/2008/11/11/do-we-see-what-bees-see/
I also like the test tube style feeders; they are a bit fussy to clean and fragile; it's fun to see their tongues slurping up the nectar [in the tube]
Good luck and have great FUN observing God's little miracle.!
I just saw your post; you called the 'hummer' enjoyment correctly !..
and you post reminded me that ' campisis radicans' is called regionally 'trumpet vine'.
We have hummingbird feeders in a few areas of our yard. We’ve spread them out to keep the males from fighting. They’re one of our favourite birds!