A lot of tricky issues here.
If You go the irish company route can manage the pension fund yourself, and this is the only way it would make sense I think to put your investments through a company - You would want to be making some good profits to make it worthwhile (there are incredible tax saving opportunities through a limited company pension).
Your money is then tied up in the company and in a pension - depending on your age and where you want to be, this may or may not make sense to you.
The question is whether you would get hit twice by corporation tax and then your personal tax rates when you tried to extract money from the company.
Corporate tax is on profits. "Profits" for corporation tax purposes consist of income (business or trading income comprising active income, and investment income comprising passive income) and capital gains. Problems occur after you've built up a company and the company is holding property, investments and cash - and then go to extract this. You could be hit with a bigger tax bill then you expect.
Your right - The more trading capital you can retain - of course means you can retire sooner - but if most of it is trapped in a pension you may still have to wait a bit
.
A tricky area, you're going to need to go to a tax specialist - I recommend Alan Moore, He's based in the Capel Building and will be able to direct you well.
www.alanmoore.ie