Nice one Aiden and welcome to the waiting club.
An extra set of air bags definitely improves safety. If your budget allows it, I'd say go for them. If not, forget about the MFSW and get them.
As for the R90's. I think the prices in the Netherlands and Ireland are comparable (ie f*cking high) cause of the bloody taxes. For example an MCS (standard manual A/C and MFSW) over here costs Euro 27,200 (in Germany you pay Euro 19,800!). A set of R90's costs Euro 2,600 in the Netherlands, so I can't imagine a set would do Euro 4,000 in Ireland.
In september there will be definitely more news of the possible black/red upholstery. Think you might even be the first one with that combo on a DS
Till then, have strength and remember patience is a virtue
PS Change and re-change whatever you want, just hang on to that DS/w combo