OP don’t get to hung up on brand Amtico and Karndean are the names you have heard of because they market to the domestic market heavily.
What you need to consider is the thickness of the tile and the thickness of the wear layer.
Most domestic glue down will be 2mm thick and 0.3mm wear layer. This imo is not robust enough for a busy household with kids, pets etc.
Look for something 2.5mm thick with 0.55mm wear layer, this will be classed as commercial grade product but will be much more durable.
In terms of click vs glue down I will always recommend glue down. As you are fitting new ply make sure the joints and screw heads are covered with feather finish and you are good to go.
Also don’t be under the illusion that if you go for click the subfloor doesn’t need to be in good condition, sure you can go over tile joints but you still need to be careful, I’ve seen click systems fail badly due to poor floor prep.
£30 sqm is crazy expensive, go to a flooring distributor and you will get 0.55mm wear layer product from Tarkett or Gerflor for around £16 sqm. This will be made in Europe and not China so tends to be better quality.
You can also get digitally printed LVT now which means the pattern repeat is 12 sqm rather than the 3 sqm that is standard. This is great if you are using wood plank designs and don’t want the same knots showing up every 12 planks!
Happy to point you in the direction of a supplier of you let me know where you are based.