Optimum line question

[SA125]

Live game that's playing very loose with numerous coldcallers.

It's a raised pot with 5 in already and you call in the BB with K9s. The raiser is in MP, he plays loose with avg aggression, and can have a wide range.

Flop is AAK none of your suits. (How much does it change your line if you have the back door fl?)

Whether the SB is out or checks to you, the action is on you. What's the best line to take for flop and turn?