Onion Helm is still available though - if you can track down an unused code voucher for it from a 1.0 Collector's Edition that is (same goes with the Garlond Goggles from the first run of the 1.0 'standard' edition). The moogle hat is gone though as that was just a perk for preordering ARR and was always mentioned as being 'limited time'. But I digress...

Although I admit I wish the glamour system of FFXIV was more streamlined like simply having an extra set of slots for 'glamour', if I remember rightly SE actually did plan originally to have the glamour system in that way, but discovered there were too many technical hurdles to overcome (mostly with extra code required to be processed server side), and with time running out (specifically, impatient players), SE took the easier option and went with the glamour system we have now. So although it's probably possible to have something like you propose, I think SE will probably just stick with the system they implemented sadly.