I have a Tria laser. As others have posted, I believe it is the only diode laser for home use. It costs $600- $750 new. I got mine used on eBay for $200.
As far as effectiveness, it works, but not all that well. It isn't adjustable like the spa lasers. I started using it on my arms pre-HRT. It did sting like it was working, but probably only killed off 15-20% of the hairs after over a dozen sessions over the course of 3 months. After about 6 months of HRT I did notice fewer and fewer hairs. Can't attest to whether it was a latent effect of the laser or just the hormones.
Hormones have done wonders overall for my body hair. Chest and belly hair has nearly disappeared completely. I did very little laser work there, so I think there HRT is the most likely source of the vanishing hair.
I tried to use the Tria on my face once. I couldn't do more than 3 zaps before having to take a break. And that was with using an ice pack to numb before each zap. 10 zaps and I was crying, so I quit.