The kit pictures a Mitsuboshi timing belt, which is good. But the listing doesn't specify brands, so there's no telling what brands the other stuff is or if you'll get the belt that is pictured.
Here are some good part recommendations to save money on timing belt components for the 2nd gen 3SGTE.
Water pump: Aisin WPT-056. Available at RockAuto, Amazon, etc.
Timing belt idler pulley is Koyo PU355816RR9D which is Worldpac P/N W0133-1631471:
http://www.amazon.com/Koyo-Timing-Belt- ... k-c1514-20
Tensioner pulley is Koyo U00392B. Available at Amazon.
Mitsuboshi timing belt:
http://www.amazon.com/Mitsuboshi-W0133- ... k-c1514-20
These are the same brands you'll get if you order the part through the dealer.
I haven't found a good aftermarket tensioner, so I'd recommend the dealer part for that. There are plenty of reliable seal manufacturers, but the Toyota ones aren't that expensive so I'd just go that route. I hope these parts save you some money while still getting good quality stuff.