thanks guys. I think Ill use the tron and maybe ill convert it to stable coin in the end. and I will add the rest deposit methods as you advised. I will add all coins that my hardware wallet accept.
Using tron will be good as that coin have a low fee of the transaction. Maybe you can add more altcoins that have a low fee, like tron. Usdt base on trc20 can be a good solution as the fee is not too high compared to etc20.
If your site is new, maybe you can test one by one of the stable coins to find which one will work perfectly for your site. And then, you can add the altcoin and bitcoin and ask for a review from the tester so you can get more suggestion from them.