You have a better chance in the UK because they have a much larger call centre industry (despite most of them relocating to India).
It has become much more difficult to obtain work permits in Ireland. If you have a large number of years of experience you could go the green card route. Managerial positions often pay in excess of EUR60,000 per year allowing you to use the green card route as an employment permit.
I believe the job has to be on the FAS database for 2 weeks before a work permit application can be started.
1400 new employment permits have been issued to South Africans in the last 2 years (excluding renewals which number around 1800), one of the highest of all nationalities so you have a chance.
The processing of employment permits have improved hugely, probably the only improvement in government services in the last decade.
* Green Cards 19th May 2008
* Work Permits 21st May 2008
* Medical Professionals 08th May 2008
* Spousal/Dependant 07th May 2008
* Intra-company Transfer 20th May 2008
All the information is available here
http://www.entemp.ie/labour/workpermits/