I would lean towards the 58cm, but I think either would work. I am 5'10" and was between a 54cm and 56. I went with the 56, but you can see from the pic that the saddle is a bit low and the stem is a little short. I preferred the feel of the 56cm, but I think my upcoming Tarmac will be a 54cm.

My son is 6'2" and thinks my 56 is way too small for him. He is really confortable on his 58cm.