Purchasable from here.
Though a short story about the love of Achilles and Patroclus isn't on my radar, I do love their story. They make a wonderful couple and the love they had for one another was definitely strong enough to last an eternity. In the Iliad, you really have no other options but to cry for Patroclus's youth and eagerness/stupidity and sympathize with Achilles's complete loss and extreme anger.
So, with all that said, if you haven't yet stumbled upon it, I highly recommend the following book. It is well-written, well-researched, and a thrill to read. Take a chance on it and let me know how you liked it.
Available in multiple formats from Amazon and other retailers.