Regarding Airport-City journey, then you have a few options: a) take
S-Bahn train; b) take "
City Airport Train" or c) take
busWith Vienna to Gyor you won't be able to book all 29 tickets at once, but if you really want you can book them in batches of 6 tickets. However don't think you should really worry about purchasing tickets in advance. Vienna to Gyor route served not just by multiple RailJet train going towards Budapest, but also many EURegio (REX) trains, you can buy tickets for 19 euro (standard fare) even before departure. And since none of the train require compulsory seat reservation, they simply can't get sold out.
Also in case you want to save some money, then besides direct international tickets you can as well opt for the option with Austrian group rail pass -
Einfach-Raus Ticket, basically you can use up to Austria-Hungary border, while for the reminding part just get separate tickets