Game Selection Help

[DCWildcat]

I'm currently playing .50/1 and 1/2 on Party and skins and I'm having trouble finding good games (hardly believable, right?)
I think it's a problem in my method. Typically I pop up 4 tables on Eurobet (my main skin, for rakeback) and 4 on party, and let GT+ do its thing. When I find a good table, I hop on the wait list. Here are problems I'm running into:

1) I'm defining "good" as a table VP$IP of >35, and "great" as a table with VP$IP Is this too selective/not selective enough?
2) I generally wait 20 hands before I make any judgments on tables. I'm thinking this is WAY too small a sample to accurately convey a table's tendencies (I've hopped on too many tables at 35-45 and watched them sink <25 within 10 minutes). My fear is that other dataminers will exploit the good tables while I'm waiting to see if they're truly good, but I think I might be overdoing this.
3) As a general question, how long should it take for me to find 2 suitable tables at .5/1 and 1/2? Any reasonable estimates?

Any suggestions about my methods/standards?