I've never spent less than $1k on an amp, so...
That Alpine one looks alright, 50W RMS per channel should be plenty adequate.
Has better crossover adjustment compared to the Pioneer unit, which is good if ya wanna run a sub, either on the same amp or trim the lower end off the mid/high speakers.
It's also a bit smaller than the Pioneer, so easier to hide under a seat etc.
Would be my choice anyway