Best payments processor for a e-commerce website?

[TuxRider01]

I'm looking for one to start accepting Bitcoin and maybe other crypto.

Here's some features that I would like:

Mandatory:

-Automatic btc to fiat conversion option available.
-Can be integrated to major e-commerce platform.

Really nice features to have:

-Segwit support
-Can also accept alt coins that can be automatically convert to fiat and BTC

Thanks!