Ulster Bank have a good offer on at the moment for start-ups. Can't remember exactly what's involved but I'm sure it includes all the usual like transaction fee free banking, free mastercard and low loan rate, and I think it also includes 3 years free online banking which would save you a lot of cash!
I would also be looking at how near it is located to you and how easy to park, hours of business etc as in business you would be making frequent trips to the bank, re lodgements etc.