There is no such thing like 'lightning BTC'. It is the same BTC, either on-chain, or comitted to a lightning channel, which is technically a 2 of 2 multisig transaction. To receive via lightning, a lightning full node or a wallet with lightning receive capability is needed. And correct, you need to open a channel first, which takes one on-chain commit, the the associated waiting time. But it is possible to transfer value at the same time by already assigning a portion of the channel funds to the receiver when setting up the 2 of 2 multisig transaction. All later value transfers inside the channel will be an just update of this transaction, which will be instantaneous. So either way, no need for a second transaction in terms of on-chain transaction. Except for the closure of the channel, if needed - which will another on-chain transaction ( channels can stay open indefinitely, though).