Here are two articles that discuss various aspects of blue and gold toning. The first is on

This article contains mostly info about iron toners, but there is a section called "bill Rowlinson's method" that may be of particular interest to you if you want a more subtle type of blue.

The second is on the site of Jonathan Bailey and discusses split toning with gold and selenium:

These maybe able to give some insights. Gold toning is very dependent on the paper and technique used to get the results you want. i would also suggest doing an archive search at photonet in the printing forum. There are several threads with good info over there.

Look forward to seeing your work when you decide on something.