Different sized chainrings

tafi

I am currently running a 39/53 chainring set up with a Campag 10 speed 11-23 cassette.

I am seriously considering chaning to a 42/52 set up for training and most racing (to get more use out of all the sprockets) and keeping the 39 for more hilly courses and use a 44 or 46 small ring for flat races and TTs

Anyone with experience of such chopping and changing?

I figure that, since the size of the big ring won't be changing much, the front derailleur won't need to be moved.

However will I need to get different length chains for the different set ups?

There are also options of manufacturer. I could get all the required parts from Campagnolo or go the cheaper option of getting them from TA.
Or I could get the 44 and/or46 from TA and the 42/52 in a matched set from Campag.

Any ideas?

Cheers