It really does depend. As an N guage modeller, I doubt that many, if any, RTR stuff will come out. It's well known even in the much larger UK market that 1 N gauge model sells for every 3-4 OO gauge item. If a good project came along and interested me and if I know the quality could be made, then I might fund it.
A 3 ICR would be a good idea - vital for the scene from late 2007 on. If you modelled that period, you could have Baby GM's, 071's, 201's. Mark 2-4 and ICR's, along with a few freight flows. A big dream of mine is modelling Portarlington pre re-building (off topic now!). As all ICR's have two common vehicles (A3 and B cars), only three bodyshells are needed. A cool feature would be working a Voith Turbo Teloscopic Schaku Coupler. That personally would be more likely from a Crowdfunded model that mainstream model.
It's always a risk to fund (even though you do get the money back if not successful). One or two failures of projects you've invested in and that's it, you are unlikely to invest again.
I will wait with interest, watching other crowd funded models and see how they get on before considering whether an Irish version would be good