If you had to choose one of the three systems to leave off the plane during design, I would suggest the spoilers would lose out.
Can't agree with that statement, and the real world tends to back me up.
Take the BAe146 for example....no thrust reversers fitted, but it has spoilers (and an airbrake too).
Many aircraft types have no reversers but do have spoilers.
I would have thought that choosing between the complexity and weight of a reverse thrust system - when compared to a spoiler system - would be a no brainer.