I think you are using unrealistically high numbers for longest single strand and total DNA. I only have three matches out of the many thousands that have more than 130 cM total and only two those have single strands larger than 30 cM. I have found 4th cousins that share as little as 24 cM total with as little as 10 cM largest single strand.
I think the most important thing is to have a well flushed out paper trail, a tree that includes not only direct line ancestors but also as many uncles and aunts as can be found and all their lines. This allows for things like name recognition in matches to target for research.