Are looking for a mesivta that meets all three requirements, is 2 out of 3 or even 1 out of three good enough? Despite the lack of punctuation, I understand you are looking for a mesivta that is
1)good
2)not too yeshivish
3)shtark litvish heimish
Can you tell us what is good in your eyes? A good group of rabbeim? A good english department? A good debate club? A good menahel?
Please define Yeshivish so we can tell you if it is too Yeshivish for you, or perhaps not yeshivish enough.
Please define litvish heimish? Once defined, we can determine if a place is shtark litvish heimish or just plain shvach litvish heimishe or perhaps just shtark.