Van, he said, the sky is the limit maa, so ... here goes,
Why not for the HU, to look at Alpine 98 series, Phantom face, Eclipse 8454 or 8455, Clarion D2 or the P9. Except for the Alpine 98 series, most of the HU got in built EQ and crossover, will be handy in future expansion and looking for that specific band (based on my sad experience unfortunately).
If only go for music without the DVD set-up in mind, you can opt for a simple set-up -front comp and a sub. For this you can go on a single 4 channel amp (2 channel for the comp and bridg the other for the sub) or 2 amp (1 for the comp and 1 for the sub).
Amp, there's a lot of good amp out there - Alpine (the F1 status), Genesis, DLS, Steg, Tru, Audison etc. depend on the budget and matching. Same goes for speaker n sub, some swear for Dyn others Focal, Eton, Morel, DLS, CDT, Scan, Seas etc.
Dont forget about the cabling, RCA and all the other goodies.
Just a word of caution.. Do not be seduced by the power of the dark side, once you take the path there is no turning back.