Spadderdock can initially appear as a good plant. Once it becomes well established with rhizomes 3"-4" diameter and 8'-10 ft long and growing into 10ft of water you will only control them with chemicals. No pulling and digging will ever get them under control. I would also stay away from lotus - all types. They are also fast spreaders in soft soils.
For hardy hybrid lilies look into the small and medium spreading types for slower growers and use the large spread varieties that will spread out quicker and grow deeper 6-8ft. Very few of the hardy hybrids will spread anywhere near as fast as spadderdock or wild white water lilies. You will be much happier with hardy lilies compared to spadderdock. They cost a little more but the long term benefit and lack of headaches long term make them well worth the money. I've fought with spadderdock, wild white water lily and lotus - never again.
For hybrids look into pink & white sensation, red paradise, red sensation, Attraction, Peter slocum (big pink), unnamed pink is economical, Colorado, Sulphurea (yellow), Charlene Strawn (Y). Some of the large spread hardy hybrid yellows & whites can grow into 7 to 8ft of water. All can easily be controlled with glyphosate based aquatic herbicides. Perry's Water Gardens in N.Carolina have very good quality and a large selection of hardy hybrid water lilies. I got almost all my 15 varieties lilies from them. Also shop at
http://texaswaterlilies.com/ 
