What data should I be looking at to target a storm chase

Shear, instability, etc, and of that what would be good numbers?

It's still catch as catch can. I'd head for any area that had the white, 'extreme' danger of outbreaks. You will then likely hear watches. Check and head for the watch area that has several warnings in it. Check the mesocyclones that have a high t.i. ( at least 5). This is a fatal error if not done---come in upwind of the twister!!!! otherwise you might find yourself at 30,000 feet in a jiffy. If somebody's doing EF scales, of course head for the largest reported one.
It's not an iideal world so you won't often have an extreme area to go to so you head for the moderate areas. Hope this helps.

You aren't ready to chase if you don't already know that stuff, sorry. Get Tim Vasquez's books about forecasting and study them thoroughly. weathergraphics.com to buy his books.