HP 82143A / HP 82162A foto coupler (encoder) - substitute

[AndiGer]

Dear Hans, looks very close to the original one. Starts with OPB as well. There are similar one's, OPB70.. I have to check the detective distance, 0.15 or 0.2 or 0.25 inch.
Maybe someone who is more familiar with transistors than me can tell the right one according to voltages. 25V or 30V collector emitter voltage? Or doesn't matter? Or need a Darlington version? For example:
http://pdf1.alldatasheet.com/datasheet-p...asheet.pdf
Thank the electronic experts for further help
Andi