I'd concur that both Fiesta and Focus STs would be a downgrade in both performance, and especially looks from your twin.
Your dilemma kind of points out what makes the '86 platform so special. There simply aren't any lightweight, RWD, agile, driver focused 2+2 sports cars with good MPG on the market. Closest thing is a Lotus Evora. Outside of that car, there hasn't been anything like the '86 for a long time.
- 370z, Gencoupe, Mustang, Camaro, and Challenger are all heavy muscle car GTs.
- Miata, S2K, Cayman are all 2 seaters that aren't practical as DDs.
- Fiesta, Golf, Focus, Abarth, are FWD hot hatches that can be quick/fun, but look dowdy compared to a low slung coupe and you're not going to find one in RWD.
IMO your best bet would be to buy your '86 when the lease ends and then mod it to be more luxurious (upgrade the interior (leather, suede, etc) add sound deadening, upgrade the stereo), or faster (add F.I.) or maybe even both. If you find that you prefer a muscle car, roadster or hot hatch, then the '86 was probably never the right car for you to begin with.