As someone who also explored the idea of using "home audio" gear in his car, I have to urge you to re-think your idea. The combination of road noise and a less-than-optimal listening enclosure makes most home audio gear ill-suited to car audio applications. There may be ways to adapt home audio gear to the car, but you will have to throw a lot of money at the problem. In the long run, I think you will a lot happier, and experience far fewer problems, with going with high-end car audio gear. I think Xtant is building the "Ferrari" of car amps, and the Diamond Audio "Hex" line of speakers is outstanding. Even if you choose the best equipment, you must still be prepared to extensively sound-treat your vehicle: DexDamp or DynaMat virtually all of the floor pan in both the interior, doors, and trunk; replace the under-carpet jute with a vinyl mass-loaded foam under-carpet pad; DexDamp the roof under the headliner; DexDamp the hood and trunk lids; etc. Without the sound-proofing, even the best car audio systems will sound mediocre.
Magical, Musical, Mini Monitors
As I will soon be finally back in the States, I will be shopping for a car with a steering wheel on the left hand side. A company called Milbert makes an audiophile tube amp for the car and someone suggested to me that home speakers work better with the amp than any car speaker they have ever heard. As I am not married and have no children, my taste runs more towards Ferraris than minivans, so I was hoping some of you might suggest the tiniest monitor with warm, musical midrange that I might try out with this tube amp. Thank you very much.