Tukmaria /sabja seeds are available in most Indian grocery stores, persian food stores and world food markets.
The amber color of the lemonade is mainly due to the use of brown sugar. White sugar might result in a faint pink lemonade.
For those of you who can't access tukmaria locally, it is available at myspicesage.com
Don't see why strawberries can't be substituted for raspberries. Puree strawberries before mixing.
If you decide to preserve the meyer lemon peels, it is preferable to sit the jars in boiling water for sterilization and let them dry completely before use.