I am attempting to install xsendfile on Amazon's own Linux AMI using

yummy install mod_xsendfile

however it aren't able to find the package. Can anybody assist with an answer please?

You can test this, but you may have to download some packages to have the ability to compile it

wget https://tn123.org/mod_xsendfile/mod_xsendfile.c --no-check-certificate

as well as for apache2 to compile it's:

apxs2 -cia mod_xsendfile.c