… I read that Sephardic synagogues are not very open to converts, (I don’t know how true that is) so I’m not even sure if I can convert under the direction of a Sephardic rabbi…
Sephardic and Mizrahi Rabbis are sponsoring Rabbis to a number of Orthodox conversion candidates, and our esnogas often have a quite a few converts (if conversion is possible in the country) — both my old and current (especially the current) esnogas have a large number of converts. Back where I was born, though, there weren’t gerim to be found anywhere in the community, but there was also not the possibility of conversion due to the lack of a beit din le'giyur in the country.
Converting under the auspices of a Sephardic or Mizrahi Rabbi isn’t very common unless you’re from a place with a larger Sephardic/Mizrahi population, but it’s doable if there is a community present. Another contributing factor for the small number of candidates seeking a Sephardic or Mizrahi community is that some people will straight up pass on Sephardic and Mizrahi Rabbis and communities for conversion, because they may come with preconceived notions and stereotypes about what’s “legit” Jewish, and we don’t make the cut.
With the exception of Syrian communities, which have a ban on conversions (another contributing factor for the belief that Sephardim/Mizrahim across the board don’t accept converts — most do, even if those communities in particular don’t), Sephardim and Mizrahim don’t tend to have worse attitudes towards conversion. Are there some awful people? Definitely — unfortunately this is a reality, and it’s not restricted to a Jewish group or another. But you also might find a wonderful community which will welcome you with open arms.
You have made your decision concerning community and sponsoring Rabbi — to which I wish you all the best. Should you choose in the future to join a Sephardic synagogue, you’ll be very much welcome.