Every thing is pretty much the same as it always has been i.e good pickup on your hub, good brakes and light than you will be on to a winner .I'd say take a look around tarty bikes http://www.tartybikes.co.uk should give you a good idea whats going on now . The whole should i get a mod,stock or 24" question is as old as the hills . It all depends on what you prefer and what you have ridden before. Even though its easier said than done the best thing for you to do is try out some bikes and see what you like