The Medovik cake could work - it's pretty dry and biscuity, but does have a big honey flavour. Maybe replace the honey with golden syrup, or even glucose.
A Joconde might be good too. It's light, firm and robust, and designed to be soaked within an inch of its life.
Failing that, you could try a yeasted cake - a savarin or kugelhopf or something.
ETA: Here's the recipe I came up with for the Medovik biscuit. It works well, especially for people like me who can only use metric