Sons of Medusa in Honour the Chapter says that if a player has access to First Founding then they can just use the Iron Hands rules to create their battle brother.  On the other hand they can use the rules in Honour the Chapter and create a codex marine, but give it +5 weapon skill and +5 Ballistic skill, and Scourge the Heretic and The Flesh is Weak 1 for 200xp

Would a middle ground option not be better?

I was thinking using the Iron Hands rules but give it +5 weapon skill and +5 Ballistic skill, and Scourge the Heretic and The Flesh is Weak 1 for 200xp instead of +5 Ballistic Skill and +5 Toughness and an Exceptional craftsmanship bionic hand.

Or even just give it Scourge the Heretic and The Flesh is Weak 1 for 200xp instead of the bionic Hand.

Thoughts?

This might should go into the house rules forum, sorry if I made a faux pax.

That seems like an entirely viable way of using the entry. It's not likely to unbalance anything and keeps the flavor right.

Use Iron Hands rules, play a librarian, fill with as many cybernetics as possible, and do more damage in melee than a thunderhammer and resist more damage than your techmarine with the Deux ex ferran power, yes sustaining it is a half action each round or to annoy your fellow players use at push as a free action each round, dont sustain it (at least til you gate the first daemon prince in)