Hello Adam!
I´ve found two links in German language about PQ 17 and PQ 18, including everything: convoy ships, escort-group ships, Luftwaffe-units, submarines, losses...:
PQ 17, look at "1.-28.7.1942 Nordmeer"
PQ 18, look at "12.-18.9.1942 Nordmeer"
Send PM if you need an awful translation.
Regards, Heuser