Try your bank, depending on your account you may have free insurance, my parents do something have a gold account(they aren't rich sadly), all they have to do is tell them when the trip is and how long its for.
I've used Direct Travel for several short trips to France, and also a 5 week holiday in New Zealand recently which ended with their underwriters arranging to fly me home first class (on medical advice), in a knee brace and on crutches. This was arranged between my getting home from hospital at 5.30 in the afternoon and 10.00 the same night. First class service from a wheelchair at Auckland, ditto through LA and ditto to the car at Heathrow Airport!
Check out the bank theory, it may save you money, especially if you buy your travel tickets by credit card.
But remember to disclose 'any' medical problems, as the insurers are getting very strict about pay-outs. A typical case recently, was a gentleman who had an heart attack in America, and after putting an heavy claim for medical expenses, it was rejected due to the non-disclosure of an hospital heart check a number of years ago, that had remained on his GP's records, which he had forgotten all about.