Zephirine Drouhan is the only totally thornless one I know. It's very bright pink, repeats & has a great scent. It's not the most disease resistant one though.
Bare root you would plant when dormant in the winter. Container roses can be planted at any time, but would need watering through the summer.
Some of the David Austin roses are recommended as shortish climbers, Shropshire Lad & James Galway are lovely ones that I've seen & are meant to have very few thorns. There are probably others.