I have some doubts as I'm not sure what his strengths are. He has scored well for the Blades but that is Div. 1. He hasn't been great in the limited chances he had at Wolves.
I remember him playing for Norwich at Ninian when he scored a terrific 30 yard shot and looked good that day (it was either a 2 - 2 draw or 2 - 1 to Norwich, it was also memorable for Chops missing about 5 clear chances which would have given us an easy win) - but he had Dion Dublin up alongside him and Dublin gave one of the best centre forward displays I ever saw at Ninian (even at 30 something he gave Jolly Rog a very tough time) so anyone with half a brain would have looked good.
However, I don't think Vokes is that quick, he is not that tall, just about 6 ft I think so not dominant in the air. If I had to draw a comparison it would be Mark Hughes but Sparkey's all round game had so much more.
I would take Jamie Mackie given the choice, quicker and with a bigger goal threat and can play wide so avoids having to shell out on a winger as well.