Hi,
For this your question answer is clear : Epic items will be unlocked at 400 CP and their crafting chance will be Legendary/2. They will have 4 bonuses and those bonuses will be increased compared to former Epic items
If you mean "strenght" as special bonus ( vitality, dex, agi .. ) , I think it is always depending by luck in craft.
I make discussion in general cathegory, because I think many questions will appear.
Jan