Recently our 7.5 month DS has decided he HATES ...

Recently our 7.5 month DS has decided he HATES his bottles. Each time we feed him its a mission. We have tried so many different things to see what the problem is (eg different teats, temperature, formulas) but nothing worked. Last night I poured the milk into a plastic cup and he took some sips from that (very messy and funny to watch as he has not quite grasped the concept of drinking from the cup). That made me realise that he'll drink the milk just not the "old" way. Has anyone else experienced this? What did you do? I dont know if I should simply offer all his milk in a cup, or can anyone recommend another drinking device (eg a good brand of siper cups). Another issue is I have all these av@nt bottles. I make them all up in the morning and refrigerate them, if I change to a cup I wont be able to do that will ? Sorry for long post but I am getting rather frazzled.