E55 is a decent projector. The ones TRS sells are pull-outs from wrecked cars, so the quality of the projector is exactly the same as it was when it was in a DOT approved housing.
You'd be hard pressed to see the difference between 5000k 55w and 4300k 35w without an A/B comparison, so he is unlikely to be pulled over for them. Is it illegal? Yes. Is it safer to have a 55w 5000K kit in DOT-approved projectors instead of going for the 55w 8000K kit in incorrectly-aimed H4 reflector housings with no glare shields on a lifted pickup truck that most retards buy? Yup.
IMO, though, I would not use anything besides OEM Philips, Osram, or GE bulbs. Aftermarket ballasts are decent (especially since they are significantly cheaper and significantly less of a hassle to install since they're already waterproof), but the bulbs in these kits are pretty crappy, and have been documented to leave burns on the inside of the projector bowl. I wouldn't let aftermarket bulbs anywhere near a pair of projectors that I cared about.
Although, to be fair, I am not sure exactly what the reflective material is. I've seen a bunch of different styles of projector bowls. All are "chrome" (the layman's term for anything shiny, although most of it is probably some form of vacuum-deposited aluminum). Some are plastic (not sure what kind, but it's thick and rigid and turns into white powder rather than melted strings when you cut it). Some are just grey primered metal on the outside and reflective on the inside. A lot of them have what appears to be a highly reflective finish on the outside, sometimes covered in transparent brown glossy paint.