I started with a Hozelok kit which included a range of drippers from single flow rate to adjustable types. It included a pressure regulator for tap connection. It even has a mini sprinkler on a spike which is a bit much for use on the greenhouse but would be more useful on a veg bed.
I also had a couple of Hozelok timers but they both failed after a few years. One was left out too long and froze so user error there but the other developed faulty switching on the solenoid valve. I tried opened up the broken one for spare parts and found out how cheaply made they were and gave up on them.
The Galcon stuff looks good but may be overkill for watering a few tomatoes in a small greenhouse. Had a look at the Antelco website too, lots of bits for making a custom setup but looks to be a business site rather than for retail sales.