Unless you have a solid reason, always go with the wpad-* flavours.
-- wpad merges wpa_supplicant and hostapd features into one binary, supporting 'everything', if you do know that you only ever need either wpa_supplicantXORhostapd, installing one of them might be smaller - but installing both, to get an equivalent feature set of wpad, would end up significantly larger without any specific gain in functionality.