The specs on that amp are a bit misleading. You don't have 300 watts max RMS, you get that at 75 watts per channel RMS bridged. Clarion is a bit sketchy on the actual peak .... but peak isn't really important unless you plan on killing your hearing.
50 watts RMS is what you're looking at ... and I love this amp. It's compact, class D, and you can shove it anywhere but the engine bay and not have a heat issue. That being said, reconsider you speakers if you haven't purchased them yet.
The 3 way Pioneer will be over powered and distort anytime you want to crank the volume. Also ... 2 way speakers sound better than 3 way. Components on a plate sound better than ovals.
If you're set on a 3 way, consider the Polk DXi690, Rock/Fos R169X3, or Pioneer TS-A6965R in that order. Same price range ... Polk being the best of that pack.. You'll be able to push the amp till your ears bleed and those speakers (especially the Polk) will be able to hand anything that amp throws at it.
You could save yourself 10-15 bucks and go with the two way Rock/Fos R169X2. Not as good as the 3 way Polk, but likely sounds better. The whole 2 way vs 3 way argument depends on the person's ear ... I personally think 2 ways have a better sound.
The nominal option would be a 6.5 component mounted on a plate. The Alpine SPS-610C or Sound Ordnance P-65C will handle that amp without problem and sound 100x better than any coax oval speaker in any configuration. All of the speakers listed are roughly similar in price.
As for the 4x10 up front ... I wouldn't bother. Anything you put up there isn't going to sound great running off of one channel or seriesed off of two. You better option would be to get a pair of 4 inch mounted on a plate and run them on their own channels in stereo.
Rock/Fos R14X2, Pioneer TS-G1044R, or Sound Ordnance P-40. Same price or cheaper than the Lanzar. all of them will handle up to 50 rms no problem. Personally ... I'd shell out 30-40 more dollars and get the Polk db 401s or dxi 400.