My first choice would be Jelle Vossen from Genk.
His scoring record over the last few years is very impressive (at all levels)
He is young, tall, strong and Belgian - just like Lukaku!
We apparently watched him before but have never made a bid. Middlesbro bid £4m for him in the summer but were turned down but I estimate a bid of between £6-8m would get him.
Buying English players is a lot more costly so looking abroad seems the safer and more savvy choice.
If we can't get him we should look at one or more from this list -
Edin Dzeko, Jermain Defoe, Philip Hosiner, Graziano Pelle, Dario
Cvitanich, Alfred Finnbogason, Filip Djordjevic, Luc Castaignos, Dusan Tadic,
Kevin Volland, John Guidetti and Demba Ba