Ah... not bare wood then? Ok, same applies, but I'd forgotten to mention that it'll need de-greasing first. Sugar soap is ideal for this, or a liquid de-greaser.
It's not essential, but working the cleaner in with wire wool is helpful. It gets it into all the crevices, and lightly sands it down as well.
Maybe brush paint into the mouldings first, then roll all the flat bits.
Your Dulux link is fine. It's a good, hard finish. The only reason I go for floor varnish is simply that floors take maximum bashing. Possibly overkill ;o)
The Junckers is silk-matt. Much the same as "satin" or "semi-gloss". Also gloss, but that's purely a matter of personal preference.
http://www.decoratingdirect.co.uk/viewprod/j/JUNSTG/