I got the matt black one because it looks better imo & i didn't need a big HDD. Get the 4GB one (that i have) then put a bigger HDD in, I picked up a 20GB HDD for £9.99 =D !
I already have a 120Gb elite and it full so a 20gb wont do ewt for me I need the bigger HDD, I wouldn't mind the glossy as i had the PS3 when it was in the glossy stage and loved it except they show all the scratches easily, the one i have now is loud when on for ages like.