[...]
Also, c-lightning is currently the only implementation which supports dual-funded channels. Such channels might be balanced as soon as they are opened as both parties contribute funds. Note that this is still an experimental feature and very few nodes support it. I opened about 3 dual-funded channels with other bitcointalk members.
Other ways to get inbound liquidity are:
In the first two cases, you only get inbound liquidity. You will then need to create a
'outbound' channel which you fund and then theoretically that should suffice to rebalance them to be both roughly balanced.