Also, I just dug out my copy of "Blue Ribbon Preserves" and here's REC: Meyer Lemon Jelly
I read the section in the front about pectin and while she doesn't give a ratio for replacing one for the other, she does go on quite a bit that liquid is preferred. It sounds as if she wouldn't substitute powdered for the liquid. So if you can scrounge it up in your area it sounds worth it.
MEYER LEMON JELLY
"A tangy jelly with an intense flavor and a shimmering translucence, this jelly is not perfectly clear in appearance. Meyer lemons have an excellent color and flavor and are recommended for this jelly, although other lemons may be used as well. Filter the lemon juice through 1 or 2 paper coffee filters before measuring."
Makes 7 to 8 half-pint jars
4 cups filtered fresh lemon juice, preferably from Meyer lemons
7 cups sugar
2 (3-oz) pouches liquid pectin
In an 8 quart stainless steel pan, over medium heat, heat the juice until warm. Add the sugar and heat, stirring constantly, until the sugar is completely dissolved. Increase the heat to med-high and bring the mixture to a full rolling boil, stirring constantly. Stir in the entire contents of both pectin pouches. Return the mixture to a full rolling boil, stirring constantly. Boil, stirring constantly for 1 minute. Remove the pan from the heat.
Quickly skim off any foam and immediately ladle the hot jelly into hot jars, leaving 1/4 inch headspace. Wipe the jar rims and threads with a clean, damp cloth. Cover with hot lids and appply screw rings. Process half-pint jars in a 200 degree F water bath for 10 minutes, pint jars for 15 minutes.
Source: Blue Ribbon Preserves by Linda J. Amendt