1:1 current balun. Either external, or a tuna that has one built in. If external, keep the tuner-to-balun runs relatively short, as even low-loss coax doesn't like high SWRs all that much (it's not like the SWR on the ladder line part is any lower, but open wire/twinlead exhibits much, much lower losses under high SWR conditions than coax does)
Jim
The machine does not isolate us from the great problems of nature but plunges us more deeply into them. - Antoine de Saint-Exupéry