Others will advise better on specific models but I'd say you should be aiming for cars which traditionally attract a high VRT rate here, as you'll be exempt.
Keep your intended market in mind. They will want something which attracts a low motor tax rate too. Rules are similar to UK here but not identical .
Personally I'd stay clear of diesel engines. There's a growing perception here that these will attract high tax rates soon.
Maybe get something you're prepared to drive yourself, in case you don't find it as easy to sell as you expected. A huge number of UK imports have arrived in the last couple of years so you'll have some competition when selling.
Finally, I'd expect a full service history with any UK car so make sure it has one, preferably from a main dealer. In fairness to UK drivers, they tend to be good at keeping service history. It boggles my mind why Irish drivers allow their cars to devalue further by not bothering to get the book stamped at each service.