The 6015B is made by Hydraulic Hobbies in China, you can find them easily on FaceBook. The ppl I know that have one don't seem to have any complaints. HH seems to have a good reputation for quality. That particular model is about 130 pounds, I hope you got a strong back
I've seen the Lesu ex's in person, quality of the kit looks pretty good, parts packaged well & the instructions well documented. But the hyds for the most part are junk & ppl who have got either, have replaced the pump and valves immediately. Also the cyls, I've noticed are tiny, especially on the 374, that's the majority of your digging power, how big the bore is. And I've also 'heard' (2nd hand info, take it for what it is) the cyls rod diameter is far too small as well & will bend if pressure turned up too much.
You mentioned unable to contact Fumotec? use this e-addy
info@fumotec.de I usually get a response within 24hrs during weekdays. I've been a customer of theirs for 13yrs. I have most of their old models, now discontinued, and some of their new ones such as the 490 ex. Once built, I get hundreds of hrs of trouble free use... very smooth to operate, very powerful, very durable, highly recommend.