You basically have two choices - work out settlement issues between you or ask a judge to do so. One is inexpensive and the other could cost you a great deal of money and even more heartache.
The best outcome is one you agree upon yourselves and the best advice I or anyone else can give you is to attend Family Mediation to resolve these issues.
In summary:
(I am not a legal professional, but volunteered in this area for some time)
Both parents are obliged to support their children to the age of 18 (or 23 if in full time education); given the age of your children, it would be understandable if that support was provided at present in the form of primary care by your wife and paid child maintenance by you.
If you wife is not working she can look to you for spousal maintenance; the one advantage of spousal maintenance is that it's tax dedcuctable in your hands, provided you have a court order.
Both parents can claim additional One Parent family tax credits.
It's impossible to say what the actual figures might be. Child maintenance is based on each parents income and expenditure - not on the child's costs.
There's a spread sheet on
www.solo.ie - it's a handy checklist but it is a bit out of date unfortunately.
The maximum that can be awarded in the District Court for Child maintenance is E150 per child per week; higher amounts can be awarded in the Circuit Court.
Re Pension adjustments and the family home - there are any number of variations as to what could happen here, again you need to consider what your best outcome would be.