The cranks you have arent flimsy at all, are you sure you dont have problems with lose crankset bolts or something ???
Yes, will be easier for you just get a shimano something cranset together with the cups. A detail... im not an expert in shimano but you have to find out if the crankset you have will match fine the group you have because with shimano, specially dura ace there are some issues mixing brands and models... With campagnolo I would say just buy whatever you want because it will work fine, with shimano is not that like a super straight forward swap...