As far as
FOC goes, check the tactics section. Canoness Rory, stJohn, and a few others have posted/been involved in the posting of some of the more effective
SoB lists out there. Deadshane is your man for
GK stuff
The colour scheme you are suggesting would be at the very top end of 'highly-challenging'. Chrome will always have to be done as
NMM, and this will be very hard to contrast with the light colours you are going to use for the trim and textiles.
As you can see from the Canoness;
SoB are very detailed and i'm not sure it would be feasible to paint the armour in chrome (esp. the chest area).
This scheme would be easier on the
GK's where the armour is more chunky, but i still think you would have to go with a darker colour for the trim etc.. for it to contrast properly.
Having said all this, i notice that there are no pics of your Tyranids up (hint, hint). You may well have the in-human painting skills required to pull the scheme off!