Why can't I get a female header from Mouser?

Looking at the SMR voice card BOM there is one item that I can’t buy on mouser.

It’s the Female 1x6 header, 2.54mm

However i’ve been looking and is this not exactly what is needed?

No, too short pins. These won’t reach the next voicecard or the motherboard when they are stacked.

Something more like this is better…
(No idea if this exact part will fit though - but they look right)

That was already in the premade cart but i didn’t know what it was for.

Also, the ATMega is out of stock, do you have any suggestions?

Perhaps this one? Seems like a heat resistant version of the usual one…