BMR and UMI products are great, can't go wrong either way. I'll tell you this: DO SHOCKS FIRST. They are the single biggest improvement to ride quality, handling, and control you can make. Do it right, and there is no downside. Call Sam Strano - get Konis. Every other mod should follow that. Doing other things besides shocks first is stupid - ask me how I know.
If you really want "rideability" (don't know what that actually means), keep you stock springs, get Konis - run the lower front perch and heater hose the rear. My guess is at that point, you'll have what you want. If you still want less body roll - get Sam's sway bars. If you want an even firmer, tighter ride and are willing to accept potential additional squeaks, get the subframes and PHB.
Get shocks first, you won't believe it's the same car. Nut up for the Konis, I wish I had- plus they allow you to lower a little too. DO SOME SEARCHING.
If you put lowering springs on with stock shocks, it will ride like **** and you will deserve it. SHOCKS FIRST!!
2005 Cadillac CTS-V, mostly stock for now, K&N drop in, home made intake tube, Creative Steel shifter, motor mounts, tranny mount, diff bushing, ICT Billet tensioner, Derale 13613 PS cooler, all synthetic fluids, basic audio upgrade