I agree with Fred: when most of the large petrol stations have tables and chairs for customers to stop and take a coffee or snack, I'm sure a garden centre would be able to provide the same.
You said, ''anymore ideas of plants people would buy?'' Spantrout: I haven't looked to see where you are, but if you are anywhere near Sliven, a visit to the nursery there would be worth a visit. It's on the road from Sliven to Stara Zagora, by the village of Rechitsa. It's been open for about 3 years, and they do a good variety of, mainly ornimental, shrubs and trees, many of which are trimmed, (sorry, I don't know if there's a verb derived from topiary, so i'll use topiariated.) They also have a greenhouse where you can find, not only the usual anuals, but again, a wide variety of exotic plants. If you're not thinking of setting up anywhere near Sliven, they'd probably give you advice, too.
I felt, when I first visited, that there would be no market for this stuff, as it's certainly not cheap. However, the place is expanding, and the amount of stock increasing. They also have citrus, olive and palms of different sizes, and they, again, can cost a small fortune.
So maybe rather than looking at commonplace plants, aiming at a more affluent market could be worth consideration. Unfortunately, we don't happen to be affluent, but I could happily stay there all day. Shame they don't have tables and chairs, and do coffee.
However it goes, I wish you all good fortune for the future.