Playoff QB/WR HELP

I’m having a difficult time deciding on who to start this week. Its my first year playing fantasy so I’m pretty jittery about being in playoffs.

FULL PPR

QB- I have cousins but with chargers defense looking extremely good should I stick with him or stream someone that’s available.
Available:
-Gabbert
-Garoppolo
-Carr
-McCown
-Mariota
-Savage

Also have a pretty solid set of WR so I need to choose between 3 of them

-Keenen Allen
-Dez Bryant
-Josh Gordon
-Jamison Crowder
-Marquise Goodwin

Any input would be greatly appreciated! Thanks a bunch