What fish can be used for 'minced fish' in Chinese cooking? I tried using mackerel which gave a good texture but was a little strong in flavour. What else can be used and readily available in the UK?

When I was in hong kong I was addicted to fish balls from the street food vendors.
I took a dim sum lesson and we used mince fish which was made from Dace (chinese mudcarp) and the teacher told me traditional fishballs were made with the same mince, but on the street they used small amount of any old fish offcuts adulterated with flour and other ingredients to give the desired 'springy' texture of quality minced fish.

Back in the UK, On teacher advice, I tried using a fresh mackerel which after slamming on the table 50 times gives a nice springy texture but when I added salt and white pepper and cooked in plain boiling water it was nice but a little strong. Anyone else had any luck? I was thinking a mix of mackerel and relatively flavourless white fish might be a good compromise.
I use a combination of Basa and what the shops mark as Spanish Mackerel (the basa usually being frozen in Australia) ... When fresh is available, I like to use Ling fillets.

I have had varied success with whiting fillets... Frozen whiting can sometimes have no flavor whatsoever.

Someone else suggested monkfish and butterfish.

Tuna made for an interesting meatball, and I used that with a Tom Yum preparation.

Addition of shell fish such as prawns also make a nice variation.