Wow, that is a lovely light system. Looks like a $15+K job, I'll guess, and really well suited to the top notch pool area.
We added low voltage lighting ourselves at the prior house and it really is not hard. You need to do a lot of planning and some calculating for voltage drops with long lines but it is pretty easy. There are lots of sources for metal light fixtures and bulbs. The direct bury line can be found in 100' reels in larger cities, pretty expensive to mail, maybe available at Home Depot as well. We used 20 watt halogens at the old house, this house has a professionally designed system using 35 watt PAR bulbs (like car headlights), much more expensive per bulb and bigger fixtures too. More expensive bulbs claim longer run times and when bulbs start burning out you will be buying bulbs by the case.
The biggest difference I see in my design and the professional one is that they used very pretty SS housing to cover ordinary timers and they used a hub and spoke system to minimize line voltage drop. A main line was run out to the yard then 5 lines for individual lights were attached inside a box similar to irrigation valve covers. There were maybe 5 or 6 main lines off each transformer, 3 transformers total. Yeah, with those bulbs it kinds looks like Disneyland here at night but they highlighted the landscaping very well and it does look nice. I think the longer distances do warrant the higher wattages compared to the old house. Took awhile to get used to it though and I have to wonder just how much of the electric bill is due to those 30 (or 40) 35 watt bulbs.
As you consider design, do remember how often you will be replacing bulbs and be wary of those up in trees for squirrels will chew on lines and the tree will grow over the line and break it, you need to allow a lot of slack for growth and reposition lines every few years before it is grown over totally.
And one more thing, just a pet peeve of mine; when lighting the front yard, do not use the path markers for outlining the flower beds. That is just wrong. Those pagoda style lights just don't work in the typical small front yard where they are at eye level to people driving by. There are so many specific styles of fixtures, for every special use, that one ought to be able to light driveways and highlight the house or plants with strategic floodlights without having lights that shine toward drivers.