First of all thanks to all your efforts 
A concern about the HW variants available to purchase: Where can a device with the specifications mentioned here be found?
I have checked with many providers on Alibaba and what they offer, has only 256 MB of DDR2 (instead of 512 MB of DDR3) and only 128 MB of NAND flash (instead of 256 MB).
Either, if there is any other recommended HW which is preferable, please share.
Hey Hamid, if you want to buy that exact model, SmartFiber sells them for somewhere in the 20-30 range + shipping.
For the moment that will work the best because the disk layout is already known.
There’s a lot of reasonably priced stuff on Alibaba which can work, but they often don’t tell you if it’s an EcoNet or a Realtek or other device, and if you guess wrong, you have a cool paperweight.
I am planning to Soon™ open an Amazon store selling some really low cost EcoNet units to customers in europe for around 10€ each. I’m not looking at selling in the US yet because trans-atlantic shipping will destroy the low-cost aspect.
Hey Caleb and thanks for your reply
The specifications in the link you provided is also pointig to a 256MB DDR2 and 128 MB NAND:
Maybe they have changed it silently?
Interesting, I would not be surprised if that was a mistake in writing the specs. I doubt they’re changing these units around that much. It could be possible that they might reduce the memory but to reduce the flash requires adopting a new disk layout so I don’t think they would do it. I notice the LAN interface specification is obviously incorrect - the device definitely has 4 ports.
After doing a bit research on this (thanks wiki and hack-gpon), It is really mostly a gamble between Econet/Airoha, Cortina/Realtek and Broadcom (I didn't even know they make xPON chips) which are the only major manufactures.
There is Lantiq which is obsolete now and and their chips were made for SFPs.
There are Huawei and ZTE chips but they are specifically used in the Huawei and ZTE routers, so they should be avoided.
Another thing worth mentioning, 10G PON capable routers (or XGSPON) almost always have the ARM chip in them. I don't why but I'm sure there is some explanation for it.
As long as you don't get a Broadcom device you are most certainly good
