1. Only you yourself know best what additional knowledge/skills complement/add value to your current knowledge base. Some may tell you that MBA is not worth the paper the degree is printed on. Others, perhaps yourself included, hope education in business administration will help further establish your credentials as an effective leader in the corporate world.
2. Since, as you wrote, so far your strong suit has been technological expertise, to round out your repertoire of managerial skills at the senior level you described, some subjects that may be particularly helpful are: ethics, organizational behavior, and managerial accounting/corporate finance.
3. Talking is cheap - I'd better shut up right here and now. Taking concrete steps to better oneself both as a person and as a business leader means more than anything else.