The electric charge cooler mod is popular. I know a guy that sells kits. If I had a chargecooler, I'd go that route. I think the S4s came with an electric pump. Or maybe that was an electric vacuum pump.
You don't want a "cheap" Esprit. There's not much more expensive, except maybe a cheap Porsche.
As for my maintenance, I pulled the drivetrain and did a new spigot bearing (clutch job), timing belt, adjust the cams (you have to pull the top of the motor off), new engine seals, AC lines, AC compressor/expansion valve/drier, Green Dot (104 MOP) pulleys, coated the gas tanks with truck bed liner, sealed the quarter windows, new parking brake cable, fixed the parking brake light switch, cleaned the radiator, recovered the seats, coated the shift cables, hoses and more I can't think of right now. You know, "routine" maintenance. I don't know if there's a single thread here. I probably posted pics of my seats, etc. in some posts.
While there are some people that do DD an Esprit, really, they are just not the DD type of car. And I daily drove a Europa once. Keep in mind that an Esprit is the most difficult to work on car I've ever come across. Before I bought this car, I never had a need to buy a mirror on a stick or stubby combination wrenches. I still have an area of pigmented scar tissue on my hand and arm from fighting with one water pump hose 3 months ago. That single hose took me 8 hours to put on. One hose. It is also the hardest car to drive on the street, but the easiest to drive hard, like on a race track, in my experience. It's like Takumi discovers after Bunta did the mods to the eight-six with the silvertop. The harder you push it, the easier it is to drive. But, you can't drive on the street like that, or at least not for long.