United Kingdom has its own sets of rules and regulations regarding granting of visa and entry of individuals. It is not possible for anyone else to bypass these sets of rules.
Since you are a student yourself so you are not eligible for sponsoring your brother or anyone else for that matter. You need to be at least a resident to invite your friends over to stay with you. The best possible course of action for your brother is to apply for a visit visa himself.
He can then extend his stay depending on his requirement. Since he can afford all, he can manage his expenses on his own. Contact the local consulate for further information.
