Pretty much all summed up by magicflyer above, the most important thing about your virtual airline is that you enjoy it.
Before you spend any money, have the premise of your virtual airline ready because you don't want to buy a domain, hosting and only then realise 3 months in you've just got the concept right, and want to get a new domain.
Jon
P.S.If you're looking for a cheap design for your website, I'm currently offering a discounted price of £30 throughout the month of January for site designs, shoot me an email office@jpderrick.co.uk if you're interested.