I currently have a Bell 18W (100W equivalent) BC/B22 2700K LED dimmable bulb (£8) in my bedroom but it's not very bright.
There do not seem to be many of a higher wattage (that are also dimmable).
Do you think the issue could be that it's 2700K, and that a color temperature between 4000-6500K would be better?
You could try using a corn bulb instead of the A19 bulb. Since you use 240V, there are a lot of dimmable bulbs on the international market (eBay for me) that work on that voltage.
example (this one happens to be non-dimmable though)
If you look at the way an A19 bulb is designed, all of the LEDs are arrayed on a small plate just below the clear part of the bulb. The design of the corn bulb lets the manufacturer array the LEDs so it doesn’t rely on the envelope to disperse the light. To find one that works for you, go on eBay and put in “dimmable LED bulb B22 base”
You might try one of these available for under $5 shipped to where I live. The filaments are LED chip-on-board and you can get it in dimmable 220V for either white or warm white.
I’m also surprised you only get 100W incandescent equivalent out of 18W LED. That must because of the design. I bought a pair of 25W, 102 SMD 2835 LED corn bulbs a couple of years for lighting my garage. They were annoyingly bright, probably the equivalent of a 250W incandescent bulb. You didn’t want to look directly at them. Eventually I replaced them with bar lights that disperse the light more evenly around the garage. The newer corn bulbs use more efficient LEDs (5630 or 5730 SMD LEDs) so are far brighter in a much smaller bulb.
If you want more output from an LED bulb, you need to spend more and get something with much more heatsinking.
One of the users here on BLF builds and sells varied sizes and powers: http://sunlikelamp.com/
