Amazon has the Pioneer Double-DIN In-Dash Digital Multimedia Receiver (AVH-1400NEX) for $200 with free shipping. Features AM/FM tuner, 6. 2" capacitive touchscreen display, Bluetooth, compatible w/ Apple Car Play, fits 4" tall dash openings.
Amazon has the Gooloo 6/12V 6A Smart Battery Charger and Maintainer for $37 - 10% off coupon clip (in Special Offers) - $9 off with coupon 4E3BRKOU = $24 with free shipping. Features winter mode, smart detection, 6-stage smart charging, suitable for 6V or 12V batteries.
Has excellent Amazon Reviews.