Other header and cam options

How about them bumpsticks?

Again, I'm using the DT. See my post on them http://www.clubfrontier.org/forums/f11/heat-shields-suck-59903/

Would I run the Tomei on a 350Z if I had one? Yes.
Are they stupid expensive? Yes. I have seen their products first hand.
Maybe it's the resale value mentality from living in Japan. You buy unknown parts (American made) and try to sell the vehicle, they are not wanting to buy it. Like having an OEM turbo remanufactured and high flowed by a stateside company. Sure it saves $1500 but multiple Japanese friends said don’t do it.
Unless you have built a domestic Japanese vehicle with imported American parts to save money, you don't know the quality control the JDM parts have.

So unless you get cams, go with the DT long tubes, high flow cats or cat removal, Uprev is a waste of money.

"did the research and found that for $60 he could have an exact replica injen intake shipped to his door for $170 less than the injen."
That was what my knock off comment was about.
What company will spend time, effort, man hours and money to design something that another company will reverse engineer? The other company will change something minor and mass produce in China for a fraction of the cost.
People go out to get the cheapest stuff and wonder why parts for their vehicle don’t exist. Who will do the above for a small portion of consumer enthusiasts that will complain about the price and then want the knock off version anyway?

What other company offers that many cam options?

Most of those EBay "Jap headers" are not made in Japan. They are made in China or Thailand. We can go on a Brand A vs. Brand B bash if you want.

I know my word means nothing here, but Tomei makes incredibly good stuff and it is made near Tokyo.

The same kids that think they need an un-sprung twin plate clutch on their stock Honda think they can change it on a Friday afternoon without jack stands. Slap on a CAI and Moms grocery getter is now a giant killer ready to fart can a huge V8. Better add that wing to improve your drag coefficient with all that big speed you now will be able to achieve.
Pick up one of those import magazines. How many are really about the mechanical aspects and not flashy rims, bling parts, stickers and some cute Asian girl? How many ricers know what they are doing on their car? They will buy anything if they think it will add power.

Lower cost, knock offs, poor design and poor quality usually go hand in hand. That’s why we get bad parts because most American import people know nothing about the cars they own.

Will those Tomei headers release 12 more horses above and beyond the DT's, even if they are a direct fit on the VQ40DE? Highly unlikely.
Are the Tomei camshafts in the Poncam or Procam variant any better than the JWT/Crower cams? No one knows. Why? Because nobody has tested them.