There may be a better solution than this, but Low's and/ or Home depot may carry a brass reducer that goes from 1/4" to 1/2". I bought most of my propane
connections from them. One solution is to put in the respected flares and use the reducer to connect them. This may not be the best solution as you end up with multiple connection in this area. If it was me, I would look at getting another regulator to minimize the connections.
Post what you ended up with for a solution.