Sperm retrieval for IVF or IUI?

In the USA, IVF is how you can confirm and choose to implant a male embryo.
I would go for IVF if I were you due to much higher success rates than IUI and because you’d like a certain gender with IVF.

Hello, while doing Ivf there is one step that is the testing of the embryos called pgt testing I think by doing that you can know the gender but here (in ireland) its only done for certain reason such as trisomy in famillies or parents have one disease cause by a gentic mutation so we didn't do it its to avoid gender selection.
For the vasectomy part did your husband past the infertility test (they usually ask mens to come back few months later give a sperm sample and check that their is no swimmers to confirm it worked )