I'd rather sign someone you know when that 1 or 2 chances come through in the tight, big games, you can rely on the guy put through to finish the chances without fail, and everything about this guy suggests he knows how to put the ball in the back of the net, he is a finisher.
As for his record in the big games being poor, has he ever been the main man, how many of those games did he start? And even if he fails to shine in the big games, a flat track bully to put away the 16 other teams in the league will go a long way to winning you the league regardless.
As for signing a 'creative forward', I'd rather leave that to signing a proper number 10 to do the creating for the forward, and let the forward rely on doing the finishing.