What do you use for your Time & Billing? LEDES files are usually
produced there. I know Aderant (CMS) and Elite can generate LEDES. I
believe smaller firm software (e.g., Juris) can do so. CMS as a matter
of fact can produce e-bills either through DocuDraft or through
Reports. However, it is not a product you would buy for just
e-billing.
You might want to cehck out http://www.ledes.org/Vendors.asp