Maurelii ensete bananas will grow TONS faster and get much bigger than any musa. That's my choice.

Good luck, from NorCal and San Diego, moved to Houston in 2007 - it's a WHOLE NEW WORLD of plants and gardening. My best advice would be to be very happy with your citrus, and gain an appreciation of the natives. Drive around in some of the fancy neighborhoods to see what they do with their yards, it will give you some inspiration. I don't know that cactus will grow that far north, but I'm sure fan palms would. Maybe even a queen palm? I am working on powering up my hydrangeas, they seem to work well in southern climates, and were beautiful in San Diego. Bougainvillas won't work, they're very freeze-sensitive. Try Dahlias, they would work, if you don't mind digging up the bulbs.

Good luck, from one misplaced Goldie to another...

I am also in zone 6b and speak from 50+ years of experience in wanting tropical looking plants and succeeding with many. But of course there have been many failures. No palm trees will grow reliably without some protection, or possibly a very protected microclimate. The only ones that MIGHT survive are needle palms (Rhapidophyllum hystrix) or maybe windmill palm (Trachycarpus) with protection.

You definitely CAN grow several types of cacti and succulents in your zone. Many opuntias and others are fine, but the key to success in our cold and wet winters is to plant on slightly higher ground so that no water sits around the plant. I have slightly mounded the area, and then mulched with small stones (1 inch size) about three inches deep. Not only does this make the area appear lever (remember the soil under the stones is mounded a little) but it reflects warmth and keeps the plants high and dry. I've grown them for years and get hundreds of blossoms and fruit.

Many camellias are perfectly hardy in zone 6b. Also, aucuba japonica, which is a nice shrub with large leaves spotted with cream or gold on green. It keeps it's leaves all winter. Google and you'll find lots of varieties. Also, some large leaved evergreen magnolias will grow well. I have a large "Bracken's Brown Beauty" that has large white flowers, and shiny evergreen leaves with a rusty brown fuzz on the reverse. Gorgeous! You might also want a nice flowering vine that keeps its leaves all winter. Gelsemium sempervirens "Margarita" is a beautiful and strong grower covered with beautiful yellow trumpet flowers in spring. Strong grower but easy to trim if needed. I also have a winter jasmine (Jasminum nudiflorum) and although not necessarily 'tropical' looking, it does have stems that are green all winter, and blooms during any warm spell in winter or spring. In fact I have a few blossoms open now. They're yellow, not unlike forsythia.

When I get a chance I will try to post some photos.

Good luck with your new garden. You have all winter to research and plan so you'll be ready when spring arrives!