Hey,
Everything depends on your budget.. i bought a 120gb SSD for mine.. runcore.. best damn investment i ever made - Not only is it faster, use less power, makes less noise.. its also more reliable.. these 1,8" pata drives creeps me out .. i'v seen to many idea..
In general, you can use any Zif pata 1,8" drive, the d430 use the same interface and type as macbookair1,1