Justigator
Sorry not a recomendation for 'quality', but this 12V system has worked well for me, and shows all the items I used.
I copied this with some updates from what I wrote to this OP:
https://www.diynot.com/diy/threads/decking-lighting-advice.466740/#ixzz77JC3Btvy
What I did was as follows:
1) Selected 12V lights from Amazon with search "12V led garden lights". Made a note of number needed and their Wattage to find total wattage (eg 10lights x 3W each = 30W)
https://www.amazon.co.uk/s/ref=nb_sb_noss_2?url=search-alias=aps&field-keywords=12V+led+garden+lights&rh=i:aps,k:12V+led+garden+lights
2) Selected LED power supply from Amazon with search "LED Driver 12V".
This has to be s 'Constant Voltage 12V' driver, not a Constant Amperage driver.
selected one that had a Wattage greater (say 25%) than that needed for the lights (so 10lights x 3W each = 30W x 125% = >38W)
https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=LED+driver&rh=i:aps,k:LED+driver
3) I selected a flat 12V Power Supply/Driver, and put a Short Mains Cable and Plug on it, and put it into a waterproof box with two Cable Gland Clamps in the bottom two holes, one for the Incoming Mains Cable and one for the Outgoing 12V cable. Not sure if this could cause overheating for bigger wattage power supplies so keep eye on this. Drilled a 3mm hole in the Drain hole of water poof box to allow any condensation to exit.
http://www.screwfix.com/p/british-general-ip55-enclosure-grey-150-x-53-x-85mm/35121
http://www.screwfix.com/p/ip55-enclosure-grey-180-x-110-x-100mm/96153
http://www.screwfix.com/p/tower-male-comp-gland-black-20mm-pack-of-2/80851
3) My 12V Cable run was 22meters, so I was very conscious of Voltage drop with this site showing significant voltage drop for me when using 0.75mm2 cable. But I found that 1.5mm2 cable was difficult to get into the small connections of my 12V Power Supply/Driver, so I went with 0.75mm2 cable and crossed my fingers. For me the LEDs worked perfectly okay and I am happy with the brightness, but it should be noted that I cannot tell if they are significantly dimmer as I never made a comparison. And you might notice this more as you have a string of lights one after the other.
So I used 0.75mm2 Black '
rubber' cable as more durable and less noticeable on fence (where I attached it). For the 12V cable I did not use the Earth lead.
http://www.screwfix.com/search?search=Tough+Flexible+Cable
http://www.screwfix.com/p/tower-co-axial-cable-clip-7-0mm-black-pack-of-100/14161
4) Joining 12V Cable to lights. I used ebays "T cable connector". Power cable in and out. And the T used to send power cable to the light.
http://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=IP66+box&_sop=12
5) Switches
To control the lights outside I used outdoor switches. So the Driver is not on all the time I put 240V into this swict and then out to the box with the LED driver in it. The cable goes in and out using cable compression glads.
http://www.screwfix.com/p/bg-1-gang-2-way-single-pole-slim-weatherproof-switch/42402
http://www.screwfix.com/p/tower-male-comp-gland-black-20mm-pack-of-2/80851
5) Notes
Big issue.... you are messing around with both 240V and 12V. Make sure you keep them separate. Make sure you are not complacent when handling the 240V cable after you have been handling the 12V cable.
Don't do this if you are not in any way happy with handling electricity.
7) question to you, Is your 240V power supply properly protected (does it have correct MCB / RCD etc protection)
sfk