Hi Tom! I too am a side sleeper and sometimes leak from my Abena L4 or ComfiDry 24/7, despite also having a booster pad. I now am wearing a pre-fold cloth diaper with Velcro from Angel Fluff Diaper Company (AFDC) over the disposable. I only leak every three nights or so and the cloth diaper effectively catches the leak so there are no wet sheets. When there is no leak I do not need to wash the cloth diaper!
I am wearing a day-time weight cloth diaper as the disposable catches most of the liquid. However, for greater flexibility (and faster drying times) I intend to order some cloth diaper flats (which need to be pinned) and see how that goes.
AFDC is a very reliable company with an excellent selection of cloth diapers.
Let us know how things work out for you.
--John