So you're wanting only an attachment that works with your current stainless steel and not an entirely new set of pipes? The pipes I bought off Aliexpress use add-on acrylic traditional lily outputs and you can buy those separately, but I don't know that they would fit your pipes.
I've been going back and forth on what I want to use on my tanks. I started with the Aquario Neo Flow but over time have grown tired of them. They need cleaned as often as glass, but because they are acrylic, over time they become hazy from cleaning with a brush. I've also had parts split/crack over time. I then went to stainless steel but I'm not really thrilled with the look or performance of those so now, I'm in the process of switching to glass and just deal with the cleaning.
Having said that, if you'd like to give the Aquario Neo Flow Premium a try, I have a brand new set of 16/22 in the box. They have an outlet diffuser that helps slow flow compared to a standard lily, kind of like the spin style lily. I'll ship to you for $35.