Look at German, and diesel( under 2 litre is better for road tax)
and because you have no vrt maybe less than 4 years old might be an option
I disagree with Amv8 with regard to specs, you do get more options on Uk cars, things like rear electric windows, Cruise control, rear parking sensors, Leather. Etc.
Yes you can get these options in Irish cars, but because Irish people are being screwed in the first place when buying a new car (21%VAT & VRT on top of that,Road tax etc) we tend to just go for basic models.(unless your filthy rich!)
On the negative side UK car generally have more mileage than Irish equivalent cars. So watch that one.