A few people (myself included) use the wheel from an early RX300. I believe if you have a 99-00 SC, the airbag connector should be plug-and-play. For the 98 and earlier it requires minor rewiring (or the use of the Toyota airbag adapter harness).

Here's a pic of mine when it was first installed...
https://1drv.ms/i/s!AqDhpJHkvUhP5BJk87YHOLEh0ro8

 

i can confirm that the 99-00 SC dont require the airbag adapter. I have the steering wheel off an SC430. I like the sporty spokes that the wood grain has on it and it fits well with the car. Gonna need a new one in the next few years though since the leather is starting to peel off it and it would cost more to rewrap it then getting a new wheel.

 

 

 

its got little teeth that only allow you to move it incrementally, the way i did it was park the car so the steering wheel is completely straight, then remove the old one without moving the steering wheel (harder than it sounds) put the new one back on as straight as i can, and bolt everything back up. Process isnt difficult but youll need to buy an adapter for the airbag since you have a 98. Also a steering wheel puller comes in mighty handy, you can rent one for free from advanced auto parts, they charge your card and refund you when you bring it back.