This idea should span two movies.
The ideal set-up to Spider-Man's greatest story arc would run along the lines of the Bugle announcing the arrival of the "world's greatest hunter," who comes to hunt "the most dangerous game of all" by invite of J. Jonah Jameson. Hell, Kraven could work in part of a ploy by Jameson to off SpiderMan due to the chaos he caused in the suit --and then of course, Kraven spirals out of control and buries Peter alive, yadda yadda yadda..
I know most of you would consider this a la Scorpion (Jonah hiring Gargan to off Spidey) but we could make this work wonderfully, just you wait.
Since Lizard is supposed to appear in SM4, Spidey could battle Lizard but lose a couple oif times before Connors slinks off to find solace in his transformation and perhaps protect the public and his family from himself. He escapes to the sewers whilst Spidey fights whoeer is a secondary villain in SM4.
After that SM4...
In SM5 Jonah summons who he believes is a devious and cunning man, Kraven The Hunter, for the movie after the Lizard appearance...Like I said, he isn't aware of the consequences hiring this deranged fellow, but after all the Lizard/Spidey brawling and the past symbiote suit disasters in SM3 JJJ wants to defeat Spidey for good.
Now listen to THIS:
When Spidey is buried and Kraven steals his identity, we all know that Kraven goes off and defeats Vermin to prove he is superior. Well, lets replace Vermin with the wandering Lizard in the sewers, and have Kraven physically overpower the Lizard---something Spidey could not---would not do because he didnt want to hurt Connors too badly.
Then Kraven, as we know, commits suicide---but in the movie it could be twisted a bit so Spidey rises from the grave to stop Kraven causing more havok. In their final battle Kraven is overpowering Spidey but finally relaizes he is better anyway---then, he commits suicide by leaping off the tower they fight on or something.
Anyways the whole point is that lizard and Kraven could be combined to make a really awesome arc.