Palm trees are your best bet if you want something easy to find. Many nursuries by me (im also in a zone 7) have very large ones for sale but they might be a little expensive. If so, then smaller palms look nice too. Arecas can be bought at lots of stores like grocery stores, or nursuries.
Also heliconias are really nice if you can find them (ones from the internet are usually small). Birds of paradise are also great and I have seen some around the 8 or 9 foot range at stores such as Home Depot for maybe around 30-40 dollars.
Philodendrons are great too and can tolerate a lot of sun, but might burn at first if it was shade grown.
Plumerias are really beautilful. Some can get very tall very fast. Im a zone 7 or really any zone below a zone 9, nursuries will not provide these plants so you will have to get them off the internet unless you plan on vacationing somewhere tropical (like Cali, Fl, or Hawaii) in the near future.
Bananas are really great tropicals. Sometimes nursuries supply them, but most of the time they arent that large. I have seen them at home depot as small plants, but they grow quick (as long as they arent dwarfs which might take 2 years to get to a noticeable size). If you cant find it at nursuries by you, the internet is where to look. I recommend musa basjoo for its fast growth and cold tolerance. It can survive your winters if its a good size, given some mulch during the winter months, and kept very dry during the winter. It wont survive the winter unless its in the ground though and it will die to the ground after a hard freeze, but resprout from the roots.
Also cold tolerant palms that you can look into such as windmill palms, sabal minors, and needle palms, all of which should survive your winters if given protection for the first 2 years (something to keep rain out and maybe some x mas lights to keep them a little warmer). They easily handle 20Fs and down to the mid teens with no damage. Mature plants of these species can handle the upper single digits for brief periods of time without very horrible damage and at least 5F when older before they start to look bad (the needle palm can handle below 0F for brief periods of time and come back fine). Just wanted to give you that info incase you are really really looking to make the yard tropical. If you are crape myrtles look great in the ground and so do evergreen magnolias.
But back to potted plants...
There are many different types of Elephant ears you can try, Hibiscus make really nice flowers that the bees do like, but dont seem to really go near often (but I have seen some butterflies on occasion, especially on the cannas).
Rubber trees also are great options, probably wouldnt like full sun ALL day long, but it can handle some very hot sun for a good part of the day as long as it wasnt grown in shade.
Hawiann ti plants are really very nice plants, usually willing to handle some pretty intense sun and the colors are amazing on the leaves. Also no flowers (well eventually it does make flowers, but not often and not until older).
Hope this gives you some ideas!
-Alex