River decision against competent player with bottom boat

This hand is 1/2 weekday afternoon session. Main V is a competent reg.

Main V (stack around 400, hero covers) opens from button to 12, hero calls from SB with 55 (yes raising is an option but we opt for flatting this time). BB (loose, recreational player, stack about 150) calls.

Hero hasn't played any hands since V sat down. I don't think hero looks at all bluffy.

Flop (36) 578 rainbow
Check, check, V bets 25.
We raised to 60, BB folds; Button calls.

Turn (156) 9
We check, V bets 80, we call.

River (316) 7. No flush on the board. V has about 250 left.
Our options:
a. jam (unlikely to get called by straight)
b. bet smaller (if so, how much can we get a crying call by a competent reg such as reader yourself with straight)
c. check-call a jam/ check raise (V is likely to check back with a straight so we miss value)
(d). I don't think bet-fold is an option but welcome different thoughts.

Another question: AP, what's our best move on the river if we have 88 instead of 55?

Thanks in advance.