The OPs club sounds very much like mine except we run two fleets - a
personal progressive aka performance handicap and a measurement handicap.
For the personal progressive we used to use Sail100(.org) which has a lot of
clever stuff to support it with, as I recall, a lot of input from the ECHO
people. It could well be worth contacting Mr Sail100, Bob McPherson.
Then, for no obvious reason IMHO, we moved to NHC (calculated by Sailwave) a
couple of years ago and as far as I can tell it is no different you still
get penalised for sailing well and rewarded for sailing badly. And the
people in the middle still grumble!
For our measurement handicap we used to use IRC but the number of boats with
IRC certificates was dwindling to the point of unsustainability mainly
because people didnt see it as good value for money. Then we discovered
VPRS(.org) and for £20 a year you get a TCF which is at least a sensible as
IRC. Now our measurement handicap fleet has bounced right back.
Some people like NHC-type handicaps and are happy to sail around and get a
result but the trouble, in my view, is that they give you no reason to
become a better sailor. As I see it, with a measurement handicap you have to
hunt down your TCF; with a performance handicap you can sit back and wait
for it to come to you.