If it says 'lawsuit model' the implication is that it is a real Ibanez, but a copy of another manufacturers product that Ibanez itself copied (like my beloved FA-100 is a copy of a Gibson ES-175). It doesn't imply that it is a copy of an Ibanez made by yet another brand.
Depends on the price. I've seen some awesome Greco LP Customs go for less than 450 recently. I think the Greco might be a better quality guitar. If you can get an early Artist, maybe an AR-100 from the early 80's I'd go for that as well.