Look at Toby's website.
**broken link removed**
It will give you ideas.
Am I correct in thinking that you want the daughter board to be perpendicular to the main board?
If that is so then you want something that is right angled, if it is to be a permanently soldered connection on both boards then something like **broken link removed** will do this well, they are Samtec numbered connectors so you can shop around.
Solder these to the daughter board then fit it into the motherboard and it can be soldered at the same time as other PTH components, it's a cheap & simple solution.
The straight ones you link to mean that the physical connection is relying on the bond between the pad and the laminate, movement could pull the pads off, if the pins go through a PTH hole then you should have a stronger bond.
I have used these on high voltage daughter boards in their thousands with little problems.
Or would you like to be able to unplug the daughter board for repairs\replacements?