Hi +Earl Judds
There are many good water filters and water filter systems out there so it's hard to narrow to just one.
One of the things we recommend when getting a new system is looking at ongoing filter replacement costs. Systems like the one you linked to are good because the pre and post filters use a standard 10" filter housing, so you'll have more options on where to get replacement filters which can help keep your ongoing costs down.
Your second question is harder to answer and depends entirely on your level of comfort with the plumbing under your sink. There are lots of great videos both here on Google+ and on YouTube showing the installation process of water filter systems, but there are many variables involved between the system you buy and your setup at home.
Joe Filter recommends you have a licensed plumber install your system.