Some of Ants albums are available on iTunes, but not all of them everywhere. It's a bit tricky to check where which album is available.
Some of the recent deluxe editions might be bargains for you in case you don't need the 5.1 mixes.
North America & Europe + ?
Harvest Of The Heart Anthology: iTunes
The Geese & The Ghost (Standard Version): iTunes
Wide After The Event (Deluxe Edition): iTunes
Sides (Deluxe Edition): iTunes
Invisible Men (Deluxe Edition): iTunes
Private Parts & Pieces I-IV: iTunes
Europe + ?, but not North America
Slow Dance (Deluxe Expanded): iTunes
Private Parts & Pieces V-VIII: iTunes
Germany + North America, but not UK
1984 (Deluxe Expanded): iTunes
Looks like there are two different Geese & The Ghost versions available in Both America, but I cannot access them.