Although they can be a bit of a pain to smoke (sometimes you just can't get your hands airtight), I think chillums are probably the best piece for small circles like the one you described -- three to five people, taking their time hitting the pipe. Although you don't get the coolest hit (obviously), you can get a pretty nice temp drop in the smoke just from its passage through your hands, and if the bowl stays lit, you can take some pretty massive hits.

As to your concern that you need a friend to light the bowl, if you pack it with half weed, half tobacco -- or just a ton of moist bud -- you can get it lit and just sit and puff on it for a great, relaxing experience.