When performing an APIO, first of all, the substance must not dangerously react with each other. Thence the more stringent packaging must be selected. In this particular case, you wish to APIO, UN 2990 Life saving appliances, self inflating Class 9 PI 955 and UN0454 Igniters Div. 1.4S PI 142. These two do not react dangerously with each other, so the APIO is permitted.
You must follow the detailed instruction of the inner packaging of UN 2990 by the rules described in PI 955. Thence you must place everything into the UN specification outer packaging of UN 0454 which must be capable for PG II packaging performance.