There have been very few realeases of Wish-related CDs, and unless an anime is produced, I assume there won't be any more.
In this little section you will find the basic info for the releases and where to purchase them online ^^

the wish soundtrack
The Wish Original Soundtrack
Produced by : Viktor Entertainment
ID : VICL-2181
Tracks by : The Ali Project
Released : 1997
Availability : in Distribution

The Wish Drama Album
Produced by : Viktor Entertainment
ID : VICL-5337
Released : 1997
Availability : ?

I'll admit that I'm not exactly an expert in finding anime merchandise online (partially because a lot of the shops don't ship to where I live, so I have a hard time finding ones that can provide me with CDs ), so if you have any further info than what you find here, *please* tell me. It would be so greatly appreciated !
I can't seem to find the Wish Drama Album anywhere online, so I can only give some info for the OST.

Wish Original Soundtrack
Purchase at Animenation -
Price : 24.95 US $

Seeing that Animenation carries it, I assume it's still fairly "easy" to get a hold of.
They do accept international orders, so I was pretty much in 7th heaven when I noticed ^^
Here are their charges for international shipping:

Postal Air Mail - $11.95
Postal Express Mail - $25.95
UPS Express - $29.95

Since it's only a CD, you won't have to pay any extra charges (like with wallscrolls or other large items)