Spinach

I like eating baby spinach and lightly cooked bigger leaves. I always fail miserably growing it though, usually jetting off to seed soon after sowing!

Can anyone give me a recommended variety for taste and not being liable to bolting?

I also toyed with the idea of using it as a green manure once I was finished with it. To get spinach year round would I need to plant different varieties?

 Everyone has something they just can't grow and spinach is one of my constant failures.

That's enough questions for now.