Yeah, an 18g is a good choice for a non-AVCS 2.0L. Or what about a SC36, or SC38, Billet? I seriously recommend a Simtek for the ECU - as it's a Live ECU and the mapper can remain more focussed in eeking out MORE safe power.
Plus Simtek has provision for a 2nd, switchable, map (inc. in the purchase price). Plus LC & ALS for £150 more.