AFS24 - is there something special or unique as to why you need to acquire the C corp.? Can you accomplish the same thing by having the LLC purchase the assets of the C Corp? By purchasing the stock of the C corp. you are also acquiring the ongoing liabilities that exist at the date of closing (both known and unknown).
I agree that in some cases if you are buying a business its a good idea to purchase the assets and place them in a new entity. However, in some cases the old entity itself might be valuable, for example if it has history (including credit history). It might have established lines of credit, used by the business, as an example, or more technical things like SSL certificates, BBB records etc.
But of course it could also carry negative history. Its a good idea to do proper due diligence both the the business and for the legal entity that holds that business.