That Hotchkis stuff is perfect, not cheap I have to admit, but they make some nice stuff.
Remember you don't need a total vehicle package, just a few well chosen components will have 90% of the benefits of a complete kit.
Go thru their website and check out the coil springs, dropped spindles and sway bars.
The GM A body is fairly light but has a seperate chassis, so more time spent boxing and bracing the frame in its critical points will make a huge difference.
A good start would also be to include urethane bushes, offset upper control arm bushes are available from Moog, the same idea as used on Mopars.
As for shocks I think you'll find QA-1's unbeatable, but Bilstein make some very good shocks for a good deal less. Hotckiss have just launched a new range of shocks too.
I have nothing against airide suspension, I just think its a modern gimmick aimed at street rodders and low riders who want 'the look'.
Ever see a vintage car on a circuit on airbags? No, didn't think so
I'd get the car home first Jimi, then evaluate what you've got to work with.
I wouldn't recommend gettin the work done over there, you're leavin yourself well open to gettin ripped off!
Sweden is full of '60's GM cars, custom parts are gonna be easy enough to get mate.
Same goes for the brakes, 13" Wilwoods look awesome on all four corners but you can build a nice braking system for half what that would cost.
Check out Scarebird LLC on the web, they make some interesting stuff to get big brakes from Foreign cars onto US spindles and hubs.
Sounds like a good car tho Jimi, them 327's just rev and rev, perfect for a 4 speed