First hand in a HU match

[shootaa]

Obviously, I could post this in the Heads Up forum, but I'm not. This is literally our first hand at the table and he is completely unknown to me (no data mined stats, etc).

All converters I know about are being bad / slow / not working.

SHOOTAA has 5 seconds left to act
SHOOTAA posts the small blind of $3
Villain posts the big blind of $6
*** HOLE CARDS ***
Dealt to SHOOTAA [7s 5c]
SHOOTAA raises to $18
Villain calls $12
*** FLOP *** [6d 7c 3d]
Villain checks
SHOOTAA bets $28
Villain calls $28
*** TURN *** [6d 7c 3d] [8h]
Villain bets $80
SHOOTAA calls $80
*** RIVER *** [6d 7c 3d 8h] [As]
Villain bets $200
SHOOTAA has 15 seconds left to act
SHOOTAA has requested TIME

Thoughts? Please don't just say call or fold, I would like you to explicate a hand range you put him on by the turn and river bets. Fwiw, the river 200 was bet quickly, if this effects your decision.