An Iyonix WITH Aemulor Pro is at least ukp270 cheaper than an Omega of similar spec. How much money are you going to need for 32bit software upgrades bearing in mind that the Iyonix ships with a full suite of internet software including Oregano2?
Don't forget also that RO4 has some compatibility issues for older software and these are not going to go away because you are running it on an Omega!
As for RiscPC hardware being an issue it has been an issue for a long long time. It was the fastest thing we had but long past its sell by date, now at least we have Iyonix.