...also, here is a bunch of helpful SSR application information from Omron on all types - opto/SCR, opto/Triac, opto/transistor, etc. They discuss a power opto/mosfet in this one where a photodiode array triggers the mosfet. They have a nice chart in there of inrush current for various devices (they mention transformers) vs. sizing of the SSR:
http://www.components.omron.com/components/web/PDFLIB.nsf/0/0F7403ADF33E949C85257201007DD5C1/$file/SSR_Tech_Information_0609.pdf
With the G3VM series small-signal opto/mosfets the led triggers the mosfet directly. 1 mS switching time, linear transfer with no distortion, and 2.5kV built in DC transient absorbtion:
http://www.components.omron.com/components/web/PDFLIB.nsf/0/744B2171FDFA7D9F862573D90061B11C/$file/J02C-E-02+G3VM+MOSFET+Relay+brochure+2007.pdf