A lipo can be any li-ion chemistry, so it could be ICR or IMR or whatever. Usually they're ICR.
The lipo itself has no protection although someone building a lipo pack could have added protection just like they could with an 18650 pack. The main difference is that 18650's have required safety devices inside them. Even unprotected 18650s have these safety devices. They're called the PTC and CID, you can google them for more info. They're a very basic form of protection from certain failures, basically like fuses. Lipos don't have these.
I don't sell batteries that aren't cylindrical cells like 18650s or 26650s etc, I can special order pretty much anything if someone's looking for a bulk order but it won't make sense after shipping from asia if you're just buying one.
And yep, a laptop battery pack is a pack of 18650s most of the time although sometimes they use lipos.