Advice on reversing camera on aftermarket Kenwood Head Unit or any good alternatives to columbus

I've replaced my broken columbus with an Xtrons HU in a skoda superb II (2012) but recently it seems to drain the battery too quickly when the car is locked. So I'm looking at getting a kenwood DMX5020DABS (assuming that doesn't drain the battery as well!)

The Kenwood will take a reversing camera but does anyone know if it will use the steering wheel position to show moving, curving guidelines like the Xtrons does?I find that feature so useful but can't seem to find out if the kenwood can do it and all the photos just show straight lines.

I'm really only interested in getting a decent FM radio that will track the radio 4 frequency changes as I drive through the UK, listening to mp3 music and using the reversing camera but hands free phone is very handy as well. So if anyone has any suggestions as to alternative aftermarket head units (that won't drain the battery or my bank account!) please let me know. I have a slight preference to physical buttons as they're easier to find and activate whilst driving than touch screen but it's not critical.

PS

At the moment I've fitted a relay to completely isolate the Xtrons HU when the ignition is off. This no longer drains the battery but obviously it loses all the radio presets.