Awesome pics. I have an idea as to what kind each is. Samson isn't a plecostomus(aka sucker fish) but some type of Synodontis.

The second pic is probably of some type of pleco.

The fish that's your favorite seems to be some type of Botia, probably botia beauforti.

the "different fish" seems to be some type of Mystus. I couldn't find it in my book.lol.

Anyway, they are gorgeous fish. Your friends a lucky person. Thanx for posting and best of luk!