I look at
a small seed company from Quebec, near my place.
http://solanaseeds.netfirms.com/catalog.html
They have many heirlooms, unusual and rare items available.
Guarda Ciello
Upward facing peppers growing tightly packed together. 6-7 cm long. Very hot. Turn red in September. Small, 30 cm plants. Can be grown in pots. From Italy. Piccante a guarda ciello.Looks like Mirasol.
Bolivian Rainbow (Arc-en-Ciel)
Highly ornamental peppers that are ripening in that order: purple, yellow, orange and then red. Can be grown in a container. About 1 foot high. Very, very hot. 80 days...
similar variety, see NuMex Twilight as told by
Indiana_Jesse
Nosegay
One of the smallest strain in the world, with tiny plants barely reaching 12 to 15 cm high. Can be easily grown in flower boxes and small pots. Also nice in borders. Small marble-size fruits grow in tight clusters. Nice laurel-like foliage. Edible fruits with medium heat. 70-80 days.
Piccante a Cuore
Short plants, 20 cm high, covered with tight clusters of small marble-size peppers. Like Cherry Bomb, but smaller. Peppers are round to strawberry-shaped, about 2-3 cm wide. Great for growing in pots or limited spaces. Very hot! From Italy.