Serious: Wechat Pay, Alipay, CUP Payment Processing - Merchant Accounts - Higher Risk

New to the BHW site but not newbie to the scene. In business on trade finance side for many years. Now venturing into online payment processing for a gaming client who asked us to manage their platform after we built and launched games for them. Client is fully licensed - above board and works with Casinos. Need to acquire or share multiple merchant accounts to receive payments and process. Any suggestions on reliable and solid service providers?