Backpacker
Whoops! Yes, 200mA.
Both units have EASA ETSO approval, so installation is good in any European state. These units are approved for aircraft below 175kts/15000 feet, but both manufacturers make similar units for higher speed/altitude.
The Filser unit has a built-in altitude encoder - you connect the aircraft static directly to the back of the unit. The Becker needs an external encoder (they were promising an encoder module to plug on the back, but I haven't seen one yet).
An external antenna is required (Comant CI01 for about $90), and this needs a ground plane - this can be foil or copper mesh on a plastic aircraft - it needs to be about 15cm diameter. You can even mount the antenna internally on fibreglass or fabric aircraft (not with carbon-fibre, as it shields the signal)
If you want to do the installation in an EASA certified aircraft, you will need some form of design approval, either from an EASA Part 21J design organisation, or via a direct minor modification application to EASA. If it's an annex 2 aircraft, you apply directly to the National Authority for the minor change (In the UK, most Part 21J companies also have a UK national design approval as well for annex 2 aircraft).
Hope this helps.