Items I would like for a shooty IG:
Reflex Scope: +1BS, yes please, work for most shooters.
Cameleoline, Clip Harness and Rope & Hook: are all ok´ish, dont go out of your way to get them, but if you got a few rarity searches and credit left, they can help.
Lucky Charm: is always good, start by getting you Captain one and see how credit and the game evolves.
Red-dot sight: If you use pistols, these can help a lot.
Tarot cards: The risk is great, but so is the reward.
Auspex: if your apponent got infilatrators, this can help contain him. (make sure the Auspex is given for a member with a 24" weapon: Autogun, Lasgun, Bolter or Hellgun)
said, if your apponent use smoke, you should get some of the visors that help against that.
But, sometimes it can be better to buy, ex. Hotshots Packs every game for 1-2 members, thet looking for and buying a new item after every game.
Hope this helps