It should be noted that both of these are basically reskins of eratohoK
FGO-K is because that's literally someone doing eratohoK with FGO characters, which I consider worth playing because Fate. eraType-Moon is not a reskin, because as the person above mentions it's a trainer game, with more emphasis on the actually sexually training Type-Moon girls, rather than the essentially talk, charm, and then fuck eratohoK offers.
eraType-moon is a trainer game like slavemaker. There's nothing wrong with it but eraSQN does the same thing better. Apart from those I'd say the playable translations are K/TW/Reverse/PM/RTP/Sumire, I wouldn't count Megaten.
Eh, fair enough. Mainly recommended eraType-Moon because it has English tutorial and in-game guide/glossary, with pretty much the only thing I remember being untranslated being personal dialogues. In comparison, eraSQN kind of tosses you into things, so eraType-Moon might be better to start with. I wouldn't recommend TW, because grinding takes forever unless you cheat, and it's not that fun to begin with. Reverse is literally Touhou characters training you, and I don't think they ever completely fixed the whole 'constantly tries to do foot stuff to you' thing. PM is fun. Megaten is complicated.