mobile Linux receiver

yes at the sponsor edison mini hd build in wifi

Most small receivers are 12volt these days (anything with an external power supply are normally 12 volt, ideal for motor homes etc)
As jakosat has stated, the edision os-mini has built in wifi which would make it a sound investment (in my opinion) as not many (if any) budget end receivers has this option.
I have one and it runs very stable (not in a motor home though).
All enigma2 receivers will record if sufficient storage is attached (usb drive/hdd etc..) although they will draw more current if an old fashioned spinning hdd is attached.
I'd recommend a large capacity flash drive (32-64 gb or more) or ssd hdd for use on a leisure battery to keep current draw to a minimum.