WHICH 4800 or 6300 CHAMP SHOULD I BUY???

Hey guys,

I recently got to 5500 ip and I was wondering if I should buy a 4800 or 6300 champ. Could you please recommend which one from the group you choose? I usually play mid and top, sometimes jg, and wreck with etc.. Can you recommend champs like these in the groups?

Thanks for the help!