This here is apparently one of the pieces of Archeotech widely available to Rogue Traders of the Koronus Expanse, they look fantastic and would be a great way to proxy space marines/primaris or other units.
Any ideas how to make one of these up? I'm thinking of 90% Iron Armour Marines with 10% Mechanicus bits. You would swap out one of the claw arms with any kind of ranged weapon!