I've been doing research on the Celica front headlights. From what I read there are really three options. I have not found any aftermarket light assemblies that are worth getting. All seem to be low output low quality (poor projectors and the covers peal/yellow in 6 months).
1st option standard OEM halogen lights and upgrading to Osram Rallye 65 watt (H7) bulbs. Slightly shorter life bulb but provide 2100 lumen for @ $35 pair. I've heard you can also find decent OEM replacement assemblies at slightly lower cost (as opposed to genuine toyota). These have 10 year limited warranty @ $175
2004 Toyota Celica Headlight Halogen Pair AM-15014302 at AM Autoparts
2nd option is an HID upgrade to the 1st option (halogen assembly).
H7 Morimoto Elite HID Conversion Kit | The Retrofit Source
This can involve not opening the assembly and just adding ballasts and bulbs (good idea to plug two holes on shield which cause glare with HID -use metal tape or similar). Can also open assembly and change to a clearer lens (tsx) which improves results. Or go all out diy and retrofit in a 2.5 HID projector in place of the 2.5 hal projector (sc430, s2k) which isn't easy in the celica assembly but possible.
3rd option is to find OEM HID headlights. These were option only after 03 and are a little pricey as a result but luckily are good quality (wide/bright). Essentially are same as SC430 projectors and can also benefit from a clearer lens if you don't mind opening it up. One pair on ebay now for like 950 but I think I've put together new for around 750 (529 assemblies, 100 ballasts, 130 best bulbs).
HEADLAMP COMPONENTS for 2005 Toyota Celica
Amazon.com: OSRAM D2S CBI Cool Blue Intense Xenon HID Headlight Bulbs 5000K (Two Bulbs): Automotive
Amazon.com: DDLT002 D2S D2R HID Xenon OEM Ballast w/Ignitor for Lexus Toyota Mazda D2: Automotive