The short answer is they can be bought new. KSport Kontrol Pro, and a few other brands. 89-92 Mitsubishi Mirage/Dodge(Plymouth) Colt is what you are looking for.
I use these: Click Me
If you want height control and the ability to dial in some soft/hard depending upon terrain, they will do you fine.
If you are looking for super finite shock control, these are not in the ballpark, as the tires are not always settled like a properly tuned shock would provide for the spring rate provided.
The guys here will chime in with other setups that are available.
You can search online for the entire community of drop shippers that offer (in stock) KSport suspension.
The coilovers have to be ordered, lead time is a couple of weeks for China to make them, and then ship them to Arizona, where they are inspected and depart for your destination.
If you get lucky and fine them in stock and stateside, you are lucky. I dealt with the runaround from drop shippers refunding a purchase because they couldn't order them for as cheap as they were selling.
There are a few warehouses that supply Mitsubishi related tuner gear and they will most likely be the only places to have them in stock if they show on their site, but call and get someone to confirm the even have the box in their warehouse first!
Also, the in house review thread: