On an 80k mile car, I would replace shocks and struts regardless of fluid leakage, especially when going with a stiffer rate lowering spring as OEM spec shocks/struts won't have as much life with the H&Rs as they would with factory springs due to not being matched. Unfortunately there are no aftermarket shocks/struts available that I know of, so we have to live with using OEM shocks/struts with lowered springs.
On my 03 mustang, I did a full suspension overhaul at ~100k miles, and in that time (though I only had the car for 20k miles, and everything was stock) I found one bent shock, one that had no fluid and would not bounce back, and my rear diff had 3 teeth missing on the ring and pinion gear, so the car had a nasty vibration and rode like crap. I put UPR lowering springs (Eibach makes them) with Eibach shocks and struts, and though I can feel every bump, rut, etc. in the road, it corners like its on rails which is amazing for a mustang. I'm moving to coilovers in front with a tubular K member, as I am doing a turbo build on that car. In any car that I have had the pleasure of working on/riding it, going to an aftermarket lowering spring will reduce ride quality (comfort) to some extent, but the handling aspect should improve.
Make sure you get a proper alignment once the springs settle (and I would recommend doing shocks/struts before that). Furthermore, the tire situation will aggravate the issue. The less 'meat' on the tires, the more prone the car is to transmit the road to you, especially with the less cushy suspension set up. I ran the BFG Sprot Comp 2 A/S (
https://www.discountedwheelwarehouse.com/Tires/details?&partno=BFG-46912&gclid=EAIaIQobChMI1Z6Pj6TS1wIVhshkCh3AKQZ1EAQYASABEgKCKfD_BwE) Not sure about that site, as I got mine from discount tire direct, but they were a pretty good tire for the price. I could feel some of the road, but generally the ride was comfy, and they hooked. I was on stock suspension though. I have heard really good things about the Continental tire offerings for the SHO, with regard to comfort, so would look there. Also, discount tire direct, and tire rack both have a rating scale on all tires offered (though it comprises of ratings for the same make of tire in all sizes) so you can get some sense of comfort vs. performance from those ratings.
