Stars $2+R
$200/$400/$50SB with

playing $15K
Fish limps UTG+1 ($10K), OK CO overlimps ($15K), I complete ($15K), BB checks ($23K).
Flop: $2K pot

I decide to lead $1K, BB calls, UTG+1 calls, CO calls.
Turn: $6K pot

Only hand that is a slight concern would be 78.
I decided to lead again, I think this is best line. What size do you guys choose and why?
Or any other thoughts/lines.