EGBK,
Nothing too close I'm afraid.
Closest is a farm grass strip called Dowth Hall. It's 1000m. There are no facilities there. It's marked in the flight guide as "Surface may be rough". I can pm you a contact number if you need it.
Seven Parks Farm is another grass farm strip, of 670m.
Next nearest would appear to be Trim, which is 580m of grass.
Looking into Northern Ireland, there is a grass farm strip of 730m at Portadown known as Tarsan Lane. It's shown on my map as "Tarsan".
If you want contact numbers, pm me. As they are private individual numbers, I don't really want to post them on the forumn.
None are close I'm afraid, and you're unlikely to be able to get a hire car delivered to any of them.
dp