Hi Rob
Have a look at the Best Buys sections for both the lump sum deposits and best value for regular savings (note maximum contribs on the regular savings; I think AIB only allow 300 pm on their highest interest account)
If your mortgage rate is higher than the highest deposit rate you can get for your extra 200pm, then putting it into the mortgage can make sense. Your mortgage provider can let you know the effect of the extra payment. Generally, extra payments go towards both interest and principal, although if you are already covering your interest, effectively the 200pm will go towards principal. If you intend to trade up in the medium term and you can get a better interest rate for your 200pm than your mortgage interest (which looks to be the case considering the regular savings products available), it may make more sense just to save that money in a savings account.
One other option, depending on your LTV is, if the extra money you have or the savings you can put towards your mortgage will bring you down to a 60% LTV, it may be worth switching to a lower mortgage rate. What rate are you currently paying?
Sprite