I decided that I don't have the room to keep the stock wheels and tires, so I put them up on Craigslist. I haven't gotten any hits on them yet, so if you know anyone, please send them my way.
I finally got around to installing the audio system over the past few days. Everything works and sounds great, I'm very pleased. The amp is 4 channel, powering both the front and rear speakers. Thankfully there is no distortion from the front speakers, as the Pioneer amp has a switch on it to cut all low frequencies from those speakers. I'm letting the rear boxes produce the lows. Overall not bad for a budget system of that period, which I think I have just over $200(current dollars) invested in.
The Pioneer GM-X304 Amp:
The Pioneer TS-TRX40's
I wasn't able to use the elusive mounting brackets for the rear speaker boxes because of the size limitations in the Samurai, between the rear seat belt retractors. I velcro'd them to the carpets and I think they will be OK like that. I was also on the fence on whether I should mount them where I did or to the tailgate instead. Mounting to the tailgate might have been a bit cooler, but would have required a lot more wiring and removal of interior panels that I didn't want to deal with at the present time. I can always do that at a later date, if I wanna get fancy.
Overall, this system replicates what I had in my old Samurai quite well and also, with the addition of the amp, enhances it greatly. Listening to the same vintage hip hop cassettes I used to listen to 30 years ago, in my old Samurai, while driving this thing down the road, really hits me in the nostalgia feels.