There is (we have) a 1-gal. aquatic & turf labeled glyphosate product called GLYPHOMATE 41 (as in 41% a.i.) in 1-gal containers, and it already contains a surfactant (mfgr is PBI Gordon).
However, I have become a quick convert to BASF's newly registered HABITAT Herbicide (imazapyr) for treating rooted emergent species; especially lilies (if irrigation and potable uses are not an issue; otherwise glphosate is your only option).
HABITAT has demonstrated exceptional root-control on species that are rooted in the hydrosoil. Glyphosate frequently has difficulty providing "great" root control on rooted-emersed plants that grow in water-depths that exceed a few inches.
I'll email a label to you from the office tomorrow.
KD

Kelly Duffie
Cypress, TX