You can look at the LMB Heeger cabinet line. http://www.lmbheeger.com/products.asp?catid=16
Their "CO" series of cabinets are very much like the Collins "S" line and Heath "SB" cabinets.
They can custom build, but a telephone call -- may provide you additional information. I believe they were the original OEM supplier to both Heath and Collins (based on both companies specific deisgns).