With the pressure from its "friendly" neighbor China PR, seems like VNPAF will busy shopping for new toys to adapt to the defense demand of the country.
Su-22 replacement?
According to Wikipedia, VNPAF is still operating up to 34 Su-22 airframes, and they would be retired in the next 5 years.
Since the retirement of the Mig-21, VNPAF has been using the Su-22 with a similar mission to the Su-27 and Su-30. As you know, the Su-22 is not so good in a dog-fight standoff and it is aging, so VNPAF has been finding a replacement for already a decade. Of course, VN is still looking for a dozen attackers such as Su-34, but also many fighters including the JAS 39, F-16V (what?), and some more Su-27/30/35.
Some more fighters?
Not only to replace the Su-22 but also to strengthen the force. Rumors say no Su-35 but a dozen of Su-57? Look like a big leap from Vietnam

The Su-57 can be a replacement of the fleet of 11 Su-27 and to be the good comrades of the 35x Su-30. However, VNPAF can operate both the Su-27 and the Su-57 to increase its dogfight ability.
Su-34 (attacker), JAS-39, and Mig-35 are still big questions. Dassault Mirage 2000 can also be on the list by its ability to collaborate with the Su-30, and VN doesn't want to entirely depend on Russia.
Kawasaki P-3C Orion?
There are rumors that in the last meeting with the Japanese Prime Minister a few months ago, VN has committed to a few P-3C for anti-submarine mission?
The quad-jet Kawasaki P-1 is also under consideration for the same business.
AEW&C
This is the biggest hole in the Vietnamese Army. But is it necessary for VNPAF to acquire such an expensive system, while the modern system of on-ground radar can easily control the entire Vietnamese Airspace?
The highest possibility is the Airbus/CASA C-295AEW&C, but VNPAF can also acquire some Embraer or Saab as well.
VNPAF can also convert ex-Vietnam Airlines ATR 72-500 and Airbus A321-231 for AEW&C as well as for anti-submarine mission.
Airbus C-295
VNPAF is operating 3 airframes for cargo mission and obviously loving the type so much. The C-295 may have a bright future in the VNPAF fleet only with the transporting purpose but also AEW&C and anti-submarine. Not a surprise of VNPAF will order and operate some more dozens in the future.
Now have a look at the key fleet of VNPAF:
Su-22: 34x
Su-27P/SK/UBK: 11x
Su-30MK2V: 35x (1 crashed)
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CASA/Airbus C-295: 3x
CASA NC212i: 3x
Antonov An-26: 30x, all grounded
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Aero L-39 Albatros: 31x
Yakovlev Yak-130: 12x on order
How do you think about those?