Bike Triple Crankset Question

Hi All,

I have noticed that the are a few keen cyclists on the Naim forum, so as opposed to registering with another forum, I thought I would chance my arm here first.

I have a 6 year old Trek SL1000 road bike that I am going through the process of upgrading; I have already done the obvious and put new wheels on (Shimano RS10s from the stock Alex rims).  I am now looking at replacing the Bontranger crankset with something a bit more slick and probably changing the bottom bracket at the same time.

The question is, without changing the front Shimano 2303 derailleur, rear Tiagra DR and 8 speed cassette, can I swap the 52/42/30 chain rings for a 50/39/30? (Looking at Shimano 105 level).

thanks if someone can help!