BGA, the one I recommended, PR26MF21NSZ, from Sharp Microelectronics of The Americas, should fit your application.
Since you are going to use the 'SSR' for DC application, here is an alternative:
"optocoupler + mosfet" may be used for your application too. For your information, the switching frequency of optocoupler and mosfet could be down to 'nano-sec'. Furthermore, mosfet has no problem to handle 100mA on-state current and 50V blocking voltage. The voltage drop across drain/source of most modern mosfet is LESS than 1V.