JBL GT-X333 is a good HU and since hardly anyone uses CDs anymore, you should be just fine. Pioneer HUs are good too but at this price range JBL has better features when it comes to future upgrades.
As far as speakers are concerned, the only brands that you can look into are JBL and Pioneer.
It would be better that you get a demo of the speakers in budget (Most big shops have demo rooms) since the taste in music and how one hears it differs a lot.
Do not listen to what the salesman says, only buy what sounds best to you and stick to the brands I mentioned.
Try to get the speakers which fit the pre defined places in the car (mostly in the doors).
Also it is not necessary that JBL/Pioneer HU will sound best with the speakers of the same brand.