South African-based Jooste is chief executive of Steinhoff International Holdings. Topping is managing director of Steinhoff's UK group of companies, which include bed manufacturing, industrial foam products and furniture import and distribution.
The appointments bring Homestyle's non-executive directorships to six.
Homestyle announced the£100 million financing deal with the South African furniture giant's European arm in May, acknowledging that the investment had saved the company.
Homestyle had been struggling with pension and VAT liabilities, as well as bank demands. As a result of the transaction, a£14 million Customs & Excise bill will be paid and£86 million of debt will be cleared. Had the deal not gone through the only other alternative for the retailer was to sell its Bensons Beds chain.