In case of asset's sale - each asset would be treated differently - as some may qualify for long term capital gain but others are not.
Both the buyer and seller involved in the sale of business assets must report to the IRS the allocation of the sales price among section 197 intangibles and the other business assets. Use Form 8594, Asset Acquisition Statement Under Section 1060, to provide this information. The buyer and seller should each attach Form 8594 to their federal income tax return for the year in which the sale occurred.
As you are selling your business using installments - the buyer will typically pay a down payment, and then the seller finance the rest so that the buyer will pay in installments over a period of time, determined in the sales agreement plus an interest.
The main benefits to installment sales is that this will generally bring a higher price than bank-financed sales, and the taxes can be reported over time as you receive payments allowing you to defer tax on capital gains.
But not all asset sales can be reported in installments - inventory or accounts receivable are not eligible for installment accounting - you should pay tax on these items within the year of making the sale, whether you have already received payment or not.
You will find reporting requirements and examples in the IRS publication 537 - http://www.irs.gov/pub/irs-pdf/p537.pdf
Let me know if you need any help.