s10 bench seat mounted cups may work also. so the rumor goes.If you have a bench, I hear tell that you can bolt one out of a later model Silverado to the frame. It's on my one-of-these-days list.
The console ashtray (assuming you have buckets) could be done, but would require cutting. You could also bend up a bracket that bolts to the hump and comes out between the console and the carpet to mount some on......