Srna costs like 15-20 million on my game and he always gets swept up by somebody with bags of cash first transfer window, so I don't see how he will be able to afford him as I certainly cant and I'm playing as Everton as well.
Try getting Miguel Torres from Real Madrid, I managed to get him for about 3 million and he's not bad, I needed a replacement as my chairman decided to accept an offer from Villa of 10 million for Jagielka which in my opinion was ridiculous but hey ho!