50nl 5b sizing spot

villain is 9-tabling 29/27/20 with 46% ATS over ~100 hands. Fold/3b in SBvsteal is 80/20(5), Fold/3b in BBvsteal are 50/38(8). i have seen him two barrel a turned FD and check back river w/KQs on 6624T COvSB regular. my perception of him is that he is probably a pretty looseish, attacking regular.

he sees me as 29/26/32 w/40ish ATS. i have been 3betting the guy to my right pretty liberally as he is very exploitable to them and hasn't yet started adjusting. villain has also seen me open/4b/fold in COvBU (his BU) so he knows i'm capable of fucking about a bit preflop and that i am bluffing in this spot (when i 3b) a pretty reasonable % of the time. thus i expect him to be c4b bluffing here at least enough to make a 5b bluff +EV

- am i correct i should be 5b bluffing some non-zero % here given reads and history?
- this a good hand choice?
- size?

PokerStars - $0.50 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

MP: $61.17
CO: $55.27
Hero (BTN): $103.83
SB: $69.21
BB: $17.15
UTG: $34.78

SB posts SB $0.25, BB posts BB $0.50

Pre Flop: (pot: $0.75) Hero has 4 A

fold, fold, CO raises to $1.50, Hero raises to $3.75, SB raises to $9.25, fold, fold, Hero raises? to?

No reason to make it more than $16