Recommendation for cloud backup of SQL databases

Hi

I look after an accountants firm with several SQL databases for their main applications.

The applications have their own basic backup feature which creates daily full backups of the SQL databases.

These currently total 20Gb - too much to backup to the cloud on a daily basis on their current DSL service.  Leased line is an expensive possible option, however is there a cloud solution out there that would allow for initial seed backup of SQL then incremental .  Anyone got similar client requirements ?

thanks