After the iRAM/640, an internal 512 Kb RAM expansion for Amtrad CPC 6128 (available on Ebay by a validated vendor), Eto was working on a 1024 Kb version (with two 512 Kb memory chips) and he just posted a link to a vendor of this 1024 Kb version on Ebay, which still needs of course no soldering at all : remove the Z80, insert the expansion in the CPU socket ! Of you course if you use a DIY kit, you will have to solder the components.

You can read the genesis of the iRAM/640 expansion in this CPCWiki's thread.