That's a lot of Grey Knights my friend. My first question would be "what
HQ choice would you want to take?" As that can drastically change how you build your army. Purifiers, Paladins, Purgation Squads, Terminators, Strike Squads, Interceptor Squads, and even most of your
HQs can be built from just those two boxes, (and I assume you'll be playing those for a while since owning all of those and just wanting to play henchmen doesn' t make sense) so picking what you build matters.
I don't think you can go wrong with 1 special weapon per 5 guys, 1 hammer per 5 guys, swords on your
PAGK (to save points for Psybolt ammo), and Halberds on your Terminators. ALWAYS take psycannons UNLESS you really want to play purifiers (as incinerators are free, and even then I like psycannons). Psilencers just don't do enough unless you're looking to only play against Daemons (and if that's so you've already won) so I wouldn't touch those. I would make 2
HQ models out of the Terminators (a Grand Master and a Libby since they're both stupid good).