Sorry, i should have been more clear.
I have been using their "combi colour" brand for the most part:
https://www.ebay.co.uk/itm/313062262218
(Check out the range of colours!)
I have also used their "painters touch" range for the smaller quantities of common colours (the red & black parts mostly).
The "painters touch" is available in both brush and spray cans - i have had no issues of reactions between the types.
No special brushes used, I just buy a decent named brand for the more visible parts to avoid lost bristles.
Thinning with relatively small amounts of white spirit makes a big difference to how it goes on, and reduces drying time. I generally work by pouring a rough quantity of paint into a disposable plastic cup, then adding small amounts of spirit (and mixing) until it is about the consistency of full fat milk.
The red parts took about 4 coats to get a density of colour I was happy with, but that would probably depend on the colour you are using (i think red is notoriously "thin" on pigment).
If you have large flat areas to cover, I would highly recommend using a small (4") foam roller to apply - much quicker & easier.
That is how I painted the van, and my O&K diesel:
20190317_120037 by
simon mace, on Flickr
(This picture was taken a few years after painting & after some pretty rough use)