I'm installing a urinal in a residential bathroom. I bought a Kohler K 10675 flushometer on eBay. The flushometer came without a control stop. The Kohler control stop for this flushometer (1056893-CP) is quite pricey at $157. There are new control stops from Sloan, American Standard, etch all over eBay in the $5 to $20 range. I was hoping to find out if I could use another manufacture's control stop. Are 3/4" control stops universal? Does anyone make a cheaper option? Are there any compatible valves I could check eBay for? All my research has come up empty. Any help or advise would be appreciated. Thanks in advance.