I have a giant defy 5, and I wanted to go to a double crankset

I got a good deal on a 105 5600 (39/53) crank (coming in the mail), and I was wondering if I could use it on my bike without much of a hassle.

Right now its got 8 speed rear cassette, and a triple FD.

I've done a bit of searching, and I found out that a lot of people have been using 10 speed cranks on 9 speed bikes no problem. But there's less information about people trying it on an 8 speed. Not sure if i'd need to get a 9 or 10 speed chain to make it work properly.

just curious if anyone here had experience with this and could chime in, thanks