I am replacing the stock unit in my 2005 Ford F-150 SuperCrew and plan
on the following set-up (I have already purchased everything but the
amp, but before moving forward thought I'd double check that I made an
ok decision on the speakers):

I have an Alpine 9847 as the head unit and have purchased two sets of
Boston Acoustic 5x7's. (I went with 5x7's because I was told that
6x8's would not fit properly).

The front speakers are the higher end NX87 and and rear speakers are
FX8's.

Will the better front speakers sound ok with the rear speakers?

Sooner or later I plan on dropping in an amp. When I amp it can I get a
2-way and amp the NX87's and let the HU run the rear speakers?

Any help is appreciated.