Hank,
It depends on the length of the feed line. For less that maybe 100 feet, almost any coax would work fine. I think something like RG-58 would work okay for shorter lengths, maybe 50 feet or less. There's no practical need or benefit using '9913' or LMR-400 and such at HF. Losses amounting to less than a dB or two are meaningless at HF unless there are a bunch of them. That's not the case with VHF/UHF, but it is for HF. If you just feel like you should use a 'better' coax, it's your wallet, knock yourself out!
- 'Doc