B4 is gonna be key to his Oki. It's hit advantage is 28 frames which you need to pull off his F4, which is +6 on block. So your opponent has to either spend meter for a get-up attack or delay their wake-up to avoid pressure. From there you can mix them up with a grab, B4, or a hop overhead. If you're reading your opponent though and they stay blocking then you can go for the 44 string. Which will also leave you plus on block.
His back throw can also be used to setup F4 but it's riskier. They got 10 frames to hit you out of it.
F34, 1+3 will give them 9 frames to hit you out of it. However you can also go for his B4 Which has enough range to hit them which will make sure the F4 lands.