Buy/get a volt meter and save yourself some money.
Why do you think any of what you described has anything to do with the battery or alternator?
New battery should read 12.5volts or higher, with engine off
With engine running battery voltage should read 13.5volts or higher, but no higher than 15volts.
With engine running turn on head lights and set heater fan to High, battery voltage should stay above 13.5volts
If that's what you get then battery and alternator are fine.
If not then you have blown fuse or bad fusible link
In the engine fuse box, find the Alt Sys Fuse, 30amp, check it
On the outside of this fuse box is a 175amp MEGA Fuse, check it
Does the battery light come on when you turn on the key?
It should, if not check Fuse #15 7.5amp in cab fuse box
1998 Ranger had 4 speakers and you said 2 quit working, all 4 run off the same amplifier so this is not a 12volt battery power issue.
Wipers have their own fuse, have you checked it?
#16 30amp in cab fuse box