i just bought two new l7s and need an amp they are dvc 4ohm. i want an amp for about 300 to 400 off ebay...the cheaper the better. i plan on getting either the alpine 9833 or 35 depending on how much money i have...i also want to get focal 5.25" components and what kind of amp would i need for these. please recommend best setup...also will i need a new alternator?