My biggest recommendation would be Solana (SOL). Solana is still a very new project and as far as I know, it is still in beta phase. Even now, its price is around $160 and its ATH level is $215. It was released to the market last year but the increase rate in its price in only one year is just insane. Think about a cryptocurrency that is increasing from a level below $1 to these levels in a very short time period like this. That's Solana.
Solana For X40 to 50x?
I think that's a bit impossible. Let's count. Now Solana's price is $158 with MarketCap $46,943,214,772 ranking 7th on Coinmarketcap. If x40 from the current price, Solana will be $6320 , with a MarketCap of $1,877,728,590,880 . It is already very high, far beyond BTC.
Indeed Solana is a good project, but for the 40X? Maybe it's not the right choice and it's unrealistic