One thing I hate is the power ratings claims of all these amps. They say 100 watts but what is that? Is it peak or RMS?
People who know more than I, have said that there's no way you can get these high wattages with only a 2 amp power supply. They say the math doesn't work out.
The amp I just bought claims to be 4 X 25 watts/channel. I'm guessing it's probably less than half of that in the real world. Still that's more power than an average boombox puts out. I've used up several in my years and when they go, I try to salvage the speakers. Most of the speakers have the power handling printed on the magnet and it's usually around 5 watts. So the amp probably isn't putting out that much.
If you don't need the FM radio, I would stick with the Lepai LP-2020a+. It puts out good sound at about half volume beyond that it starts to distort. It's only around $20 too so that's a good thing.
The fact that my new one plays from a USB stick or SD card isn't of much use to me since it has no shuffle feature. It also does not display song titles, just track number and time elapsed. The display is nice to have for FM stations. I plan to connect an MP3 player to one of the inputs and control the music from there.
I can't comment about your speakers. I just don't know if they will sound good or not.
Here's a video from a guy who put the 2020a+ through a oscilliscope, it may help you decide.
Edit; Yes they are car speakers and bigger 3 ways would probably be better. As you probably know, car speakers vary widely in cost and quality. Space is an issue for me.