Just to give you some insight on this...
I don't recall any DIY on this or if anyone did this on their Gen8 Corolla. If someone knows of it, post it up in here. Given that the 98-00 had DLR and the single headlight bulb setup of the 9003 (high and low) compared to the 9005 (high)/9006(low beam)in the later years, it's going to be a decent amount of work. Probably best to have a donor car or a junkyard which you can rip stuff out. Since the fogs are not pre-wired in the 1998-2000, you'll probably have to pull the harness out of the donor car as well. There are some electrical differences too between the 00-01 to the later years interior-wise too that I know of. Not sure if you can simply drop in the signal stalk into the early years...or could just get a switch somewhere on the dash for the fogs.
I do know there are some people who did a similar conversion in the Gen4 Camry forums from the single bulb setup in the 1997-1999 Camry to the 9005/9006 headlight set up in the 2000-01. That required new bumpers, splash shield for the front wheels/fenders (due to bumper being different), cutting some sheet metal off the front of the car to mount the bumper/headlight and wiring harness modifications. Not sure if the Corolla would require this much work, but would be a guesstimate.