As far as I know these are your choices....
Factory TRD flares (HUGE and UGLY-I know, I have a set)
Ivan Stewart flares (great looking-good luck finding a set-way overpriced!)
Bushwacker flares
ATS flares
EGR flares
Southeastern Edition Toyota Flares (smaller that the TRD flares)
Take a look at Performance Products website they have a good selection but you can find them cheaper elsewhere.
The ATS flares are available on the auction site by seller: autoaccessory4u for $239 plus shipping or at their website
99-04 Toyota Tundra ATS Custom Style Fender Flares for $247) Probably the best price you will find on flares.