i am looking to buy a humminbird 575 fishfinder is this fast and good enough for striper if not give me some ideas of one to check into

What are you wanting to do? (troll or jig) Trolling it'll work fine but jigging you'll need something faster.

basic trolling w/ shad

Yea, the 575 should do what you want.

Sonar Echo Enhancement Technology is so sensitive it’ll track a jig to over 40ft and separate targets within 2 ½ inches
Microdynamic transducer design slices through water for reliable readings up to 70 mph
If you are trolling 70 mph I don't think you will get many hits!
Yep this will work just fine for the lake or the ocean.