The flexible hose rated for propane is a composite and is a lot more than just "rubber." Look for the certification printed on the hose. Any good hose shop will have it and can explain it. While having pressed-on ends can speed up the install, be Real Sure you know the exact length of each section.
Last install I did was a few years ago, and high quality ss hose clamps were used on barb fittings.
As noted, you cannot have any hose joints or T's beyond the sealed tank compartment. I made up a brass manifold with a quarter-turn valve for each circuit - cooker and bulkhead heater. The tank compartment will have the solenoid shutoff valve, and often a gauge, as well.
Handy for cooking (and heating) but you HAVE to follow proper install practice. I have seen the "morning after" remnants of a sailboat that had a destructive explosion, and it rivaled anything seen in an action movie.