Hmm.
First, as some other posters have said: Circumaural does not entail open. No idea where ZombieX gets this from. Circumaural just means "around the ear." Basically, the OP wants full-sized cans.
Two, the OP wants portable cans which isolate well. Circumaural portables never made sense in my brain, but maybe that's just me. As someone else has said, the Denon AH-D1001s do not isolate well. Furthermore, they're ugly worn. Ergo, they are not portable. Finally, IMO, they do not synergize well with the Fiio E3 amp.
Third, both Sennheiser HD25s are supra-aural. Also, I'm not sure if even the SPs qualify as "100-ish". Depends on what "ish" means, I guess.
Fourth, the HD280s are not bad suggestions, actually. However, people are rather divided over these cans with regards to SQ. It's one of those "controversial" headphones. As for looks: They look a hecukavalot better than the D1001s and, IMO, better than the cheaper Senns (HD201, 212, etc.). Do a Google Image search, for a preview.
Fifth, why is circumaural preferred? I noticed the "if possible", and was wondering why your friend likes these better. It's a bit odd for portability. We might be able to suggest a supra-aural can that gives you the particular features of circumaural cans you're looking for.