Just posted a question about the difference and which is the better unit to use in a residence that already has all the ductwork for a traditional system. Just thought I'd put the right subject.
See my recommendation on your other thread.
Have you looked at the Carrier Infinity GreenSpeed series?
This may be a better choice than Daikin.
Here is a link that might be useful: Carrier Infinity GreenSpeed Series
I like my mini splits. Look at the manufacturer's web sites, Daikin, Sanyo, Tosiba, Mitsubishi,.... On one extreme, if your duct system is inside the building envelope and works well, you will save a lot of money keeping it. On the other extreme, if you have leaky ducts outside of the building envelope, you might consider a radial change.
I have posted some comments about my 7-room mini-split installation recently. Look those posts over.
There is one on under "Central HVAC alternatives needed" Minisplits will cost more.