Stuff; where have you heard/read that Liam uses a Roland U-220?
Everywhere :-) I have some pictures of Liams rack with the U-220, i've read it in the book by Martin James, and you have to check out the awesome 'Equipment' section on Juges site (click: Musicians --> Equipment).
If you're looking for the 'natural' strings Liam used so much it's the U-220 you're looking for.
I have some other Roland modules with strings, and they sound lame compared to U-220. But remember no hard velocity, play pretty soft if you want to have this special "Jilted" vibe.. The U-220 also has internal Reverb and Chours, so you can add some nice stuff without an external FX-box.
I think it's definately worth to buy. And it's really cheap nowadays (due to it's age, it came out in 1989 :).
There is also a Roland-rackunit called U-110 which is quite similar to the U-220. So i don't think it's a disaster if you only are able to get a 110 (they may even be cheaper).
If you get the chance, play it before you buy it so you'll know what you get.
Maybe unnecessary information; but when i first got my U-220 the "G-Force" string sound was number 066 and 067, and the strings we're talking about! had number 068 and 069.