LLB - I'm pretty sure their shocks take the standard 2.5" springs. That's a pretty standard coil-over spring size and refers to the spring ID (roughly). So an OD of 3.25 sounds about right.
You'll find most coil-over shocks made in the US (and elsewhere) use this spring size as standard, and there's lots of manufacturers of springs in this size and a variety of lengths and poundage.
FWIW, there are a limited number of shock manufacturers that use a 2.25" spring and also a 1.9". The 2.25" is was a popular size back in the 60's/70's and looks to have mostly been eclipsed by the 2.5" now. The 1.9" is for a small body shock, very few manufacturers offer this size (mostly European).
I'm also interested in the Aldan shocks after looking into just about everything out there. Good pricing and taylored for a variety of uses. The only thing I'm not too sure about is the finish on the shock body - they don't list any kind of surface finish or protection and bare aluminum corrodes in the elements. A powder coat or anodize would do the trick.
Another one I'm interested in is the Varishock made by Chassisworks. Looks to be a pretty nice unit but a few more $$$ - about $700 double adjustable with springs.
http://www.cachassisworks.com/vas_featured.html
Others of interest - Afco, AVO & Koni (more $$$). Not sure about QA-1, that one seems to be sort of a "fast food" shock - waiting on reports from Volkdent about how they work in his IFS makeover. QA-1 looks to be the other "inexpensive" option though, besides Aldan.
Jeff