They are a company from the Philippines. There are a few people on here that seem to have gotten parts from them or know the company personally (thinking of MPH people).
A good intake actually takes in fresh air from the outside... Not the ambient HOT air that's under the hood. Other than a "free flowing" tube and filter, I don't see much with the SL intake.
I have not seen the header of the mirage and can't tell if it's worth replacing. I can tell you that a good intake, full exhaust, and tune all together will yield best results.
The problem with the MAF sensor is they're very finicky and companies spend a lot of time figuring out how to trick the sensor into not thinking something's wrong.
Most DIY air intake kits on MAF cars result in MILs.