AutoArt is probably the top of the line for Suby die casts right now. The Trofeu is a good smaller scale rendition.
Colors cannot be custom ordered, though if you just HAVE to have one the color of your car they can be disassembled and painted with some difficulty (it will ruin the collector value in the future, however).
A good online source for most any die cast is www.ewacars.com.

 

you can search on ebay. they have quite a few there.
if not to buy, you can see what's out there.

 

When I was younger, I used to buy Maisto cars all the time. They were low-priced (especially at Sam's Club), and their models were pretty accurate, moreso than models like Bburago or a few other more expensive ones. (I don't know if they make Subarus or anything like that.) They even had "functional" suspensions with springs and stuff, so it was pretty neat. But they mostly had supercars. If I remember correctly, the Maisto cars I had (all in 1/18th scale) were the Dodge Viper GTS, Ferrari F50, Ford GT90 concept, Jaguar XJ220, Lamborghini Diablo VT, Lamborghini Diablo Jota, McLaren F1, Mercedes-Benz ML320, and Porsche 911 Cabriolet (993), among others. I also had some other ones by other companies, but Maisto was definitely good stuff.

 

AutoArt is my favorite and the only one that I know of that makes any Subaru's in the 1:18 scale I highly recomend them!. Another great maker is UT although I have never seen a Subaru in them, they are highly detailed as well.

PS: Anyone know of a 1:18 scale Legacy ? hmmmmm

 

UT is alright. I had a McLaren F1 LM that I had to special order from Exoticar. It seemed to be more realistic as far as dimensions, especially when comparing it to my McLaren F1 by Maisto. But then again, I did have to pay a bit extra (since it was ordered from a magazine as opposed to just buying it from Sam's Club). But the Maisto seemed to be more into details. For example, the disc brakes had dimples in them (since they were cross-drilled), whereas the UT model I had just had black little dots and a "fixed" suspension.

Oh yeah, there's this one company that made a lot of the imports (NSX, Skyline, etc.), but I forgot the name of the company. Their cars were pretty expensive, too (like around $60 or $70).

 

Ebbro out of Japan makes really good models of all sorts of Japanese cars and some European. They should have Subi models.

Also, I still think Autoart is the best!

Try www.exoticar.com for big selection of all scales...