I would say that S/R ratio is a pretty good metric. But I think you should mainly focus on reach, since the stack can mostly be altered using spacers - you don't have to slam the stem. See if you can find a bike with a very similar reach, and can modify the stack to meet the effective stack measurement on your old bike.

Most of the geometry figures on a bike determine handling and such. You don't need to worry about standover since you have long legs. You may need to worry about seat tube angle, though. Long legs means a lot of seatpost extension. You could end up with a saddle that is too far back this way. Similarly, look at the seatpost setback on the new bike. If the seatpost is very setback, and the seat tube angle is slacker, you're going to have a harder time getting the saddle as forward as you like.

Also have a look at crank length since the optimal fit around a shorter crank will increase reach and reduce stack (decrease S/R ratio). It will also move your center of mass higher and further back.

Stem length is obvious, but handlebars that are wider or narrower than "just right" will significantly increase your reach. I went from 42 to 38cm bars and I would say that felt like a 10- 15mm increase in stem length.

EDIT: unfortunately, there is a lot that goes into how a bike *rides* that cannot be determined from S/R. Two frames could have identical stack, reach and components but ride differently. Generally, though, shorter wheelbase, steeper head tube angle, higher BB (less drop) and less trail means more "twitchy".