They're a commercial organisation - they will want to sell you their services - you can always ask them to call round - listen to your needs and give you a quote.
Alternatively you can ask a neighbour - one with a nice garden. Or use a garden related social media site.
Will it be a good idea?
Your decision based on how much money you might want to spend and how much work you're prepared to do - but above all - the scale and scope of the changes you envisage.
Good Luck...
April 2017