Bro I have been out of the market lately, but I just helped a friend buy a basic Pioneer series HU and a pair of Clarion (made in Japan speakers) along with the speaker shelf, altogether in approx 13.5 (HU 7.5k + SP 4.5k).
I personally found the Clarions to be better then the available speakers by kenwood and pioneer in that price range.
So you will end up spending at least 12-13k on HU and SP alone. Rest you are left with 6-7k in which you would need an amp and a sub.
Suggestion:
Bump your range upto 25k, get a new decent 4ch amplifer and maybe a used sub plus box+fitting. Along with a base line HU and normal speakers.
At the end of the day, it entirely depends on the budget you have. The more the money, the sweeter the sound. But then again, dont spend too much on a cultus, as at the end, you will not get your money's worth, as the outside noises will spoil most of your experience!!