The Evo 4 will not be appreciating in value very quickly I think. Though its body styling was something of a leap from the III, and contemporary evos still look a lot like the 4. I think it was also the first evo that was running at 276hp. I suppose in this regard it might be considered a bit of a classic.
At any rate, I would say there's little that's going to rival the combination of practicality, performance, and price that an older evo offers. Other sports cars a the price point you're looking at are going to have much less room (RX-7), cost more (R32 GT-R), or lack the same kind of performance (Silvia, Type R civic, idk). Obviously a V or whatever is going to perform better, but also cost more. Other ralliers like the Celica GT-4 and WRX STI are about on par with the evo so I guess thats up to preference and availability.
oh and if you're importing shit from brokers like velocity cars or buying from someone who bought from an auction you should be familiar with the auction sheets. AS far as I know all vehicles put up for auction are inspected and graded, obviously you dont want to be buying something with an R grade or whatever. If you're buying a car that was sold at an auction, you should be seeing that auction sheet before you buy.
Check out these links for info on how Japanese auctions work. That site is also another company that does importing, so you can consider their services too I suppose. Though I'd definitely do research on a company before becoming a customer..
Japan Car Auctions, Japanese Used Cars, Japanese Car Auctions
How to Read Auction Sheets in Japan, Japan Auto Reports, Japanese Auction Sheets