If I lived close by a shop selling Kalkhoff bikes, I'd probably buy one of their machines. On the other hand, if that shop sold only KTM bikes, I'd buy a KTM.
If it were the case that I lived in the middle of nowhere and had it in mind to spend a couple of grand on an EAPC, I'd take one or two days out to visit specific bike shops to actually ride the bikes and meet the people who sell them. I think it really goes without saying that any previously unheard of dealer with only 5 minutes in the business would not be on my list.
Even the shallowest research of the pages in this forum will soon make it clear which dealers have been around for a long time and generally speaking, those people don't deal in rubbish, they treat customers fairly and have back-up resources to ensure peace mind. They will also have the best warranties in the business in that regard.
All that said, you don't need a Masters in electronic engineering to actually fit a ready-made kit to a bike of your choice but you might want to invest in a decent multimeter if you don't already own one - just for that day sometime in the future when something goes wrong. You will then be able to seek advice and guidance from the forum, 24 hours a day, 7 days a week. That's when the meter may be handy as you might well be asked for some readings at various points in a fault-finding trail.
Good luck,
Tom