The third choice beats the other two hands down.

The LADO retracts aren't pheumatic. No hoses, little tanks, nothing of the sort. And no mechanical retract adjusting or rigging pushrods or servos.

Screw them in wherever the retracts go, plug them into a Y and the Y into the RX, and fly them.

Both planes in the attached have them retrofitted. Simply pulled the OEM retracts and servo and rigging, and screwed in the LADOs. (and plugged 'em in, of course) I did put struts on 'em too. That took more time than the retrofit.