My car before the LS was a '94 Thunderbird, essentially the same as your Mark, minus air springs and 32valve engine. It was lowered in Intrax springs, and that's about it. It handled good, no body roll.
You'll love the LS. If you're not after a bunch of horsepower mods, the LS is IMO superior. It leans a little more, but actually handles better. For me, even my first gen LS was a power increase but for you, it will be pretty even. The weights are pretty even. Better weight balance in the LS though. And the LS did a great job reducing sprung and rotational weight with aluminum control arms everywhere, knuckles, and like the Mk8, driveshaft. LS has a passive rear steering to help corning. Handling for the size is its bread and butter. If the aftermarket and ability to make it go faster was why you liked the Mark, you probably won't enjoy the LS as much... unless you your own power adder. You'll have to make custom stuff yourself though. Even with my universal nitrous kit, I had to customize the fuel pump setup.
Read the sticky threads to find out common issues. If you turn your own wrenches, most of them are easily managed.