I bought all my stuff at breakwater marine but had the factory install. Breakwater will install as well and when you buy from them they may be a little more expensive, however, they warranty for 3 years and if you run into problems they come to your boat and either fix it or give you loaner equipment until yours is fixed. They say you will not be a weekend without your boat or some electronics.
They have already made a trip down to my boat to look at an issue so I am pretty happy.
Check with CalmDay and Chase This! One of those guys has a good experience and install with someone as well.
It is like my boss tells me...... Quality, Price, Quick. Pick 2 of the 3 but you can't have all 3. You get what you pay for but you ALWAYS pay for what you get.