Funny you mention this. I can't find the project to unlock them in the store. I'm T5 on 2 toons and its the same for both. Also on both toons I can't find any projects to unlock Borg space weapons in the store. I actually thought the space weapons and doffs had been removed from the game for some reason :s
There is a character copy bug. When you transfer a toon over to Tribble your Reputation status does not get copied. You have the passives unlocked, but the Tiers will stay at T0. Thus testing is not possible - at least until you decide to grind reputation on tribble all over again.