Possible for equity sale of LLC treated as asset sale for taxes?

Like everyone else said, it depends on how the LLC is taxed. For federal tax purposes, an LLC can be treated as a partnership, a disregarded entity (in the case of a single-member LLC), an S-Corp, or a C-Corp. In all the LLC transactions I’ve handled that were structured as stock deals, the entities were classified as partnerships.(Technically, LLCs don’t issue stocks, so these transactions are referred to as unit purchases or membership interest purchases.) In all of these, we as a buyer obtained a full step-up in basis. This step-up is achieved through negotiating and agreeing on the purchase price allocation. As a buyer, you would typically prefer to allocate higher values to tangible assets to optimize tax benefits (e.g., allocating more value to equipment that can be depreciated over 5 years rather than to goodwill, which is amortized over 15 years).

You should also explore an F-reorg if the 338(h)(10) isn't possible. I agree you need to get professional advice from a tax advisor.