Pioneer DEH 80PRS has been a wildly popular head unit for a while now as it has time alignment, crossovers, and EQ built in. They can be had for just shy of 300$ these days and it would be a top recommendation if you don't need a full DIN screen or anything.
I always suggest JBL/Infinity lineup or fairly priced good performing components. The 150$ ish price point should buy you some decent sounding components through them. Sundown SFB amps are a fair value and backed by the best warranty in the industry, not sure when their 4 channel is due to release though.
Also keep an eye on SoundSolutionsAudio website, they often do several rounds of deals running up to Christmas and you might find some deals there. Most of what they sell is good but if you're uncertain run it by us here before you buy.