In short my car has been in and out of Audi (2003- Not S-Line, just Quattro Sport) with suspension problems and i now have new front 'trailer arms', they have replaced only the front suspension as it has has numerous knocking noises and squeaks and rattles and they won't replace the rears as technically there isn't a fault to diagnose at the back, blah blah, Audi won't honour the warranty to replace non-faulty parts, whereas my reasoning is that its a car with 60k on the clock and i'm not happy that i have fresh shocks at the front and
some new bushes and the original shocks at the rear - and the problems still aren't resolved! The car is finishing its warranty in two months so its a case of sod it...
My reasoning for Weitec shocks and springs is purely because i like the KW brand and quality and there is no discernable difference in quality in this choice over the KW or HR spring/shock combo for my style of driving (i don't want a go-kart!) The drop will be 35mm, but again, i'm not an
aesthetic person, i want a decent supple ride that'll leave me with my fillings!
Having previous been of the VW clan i have been out in a lot cars done with Weitec shocks and H&R, the ride is more smoother and compliant than the standard Audi suspension in my car - as a point of observation the S-Line suspension against my car's standard 'Quattro Sport' suspension is miles better in the first place so i know i will see a significant leap in quality when the kit is finished which will bring the car right up to scratch.
On the ARBs subject, again back to my Golf days H&R ARBs are for me a known quantity and there's little more in the choice other than that, but with the addition that all the bushes will be replaced and i will have a car with significantly reduced roll, a little lower and better 'B' road suspension.
Again back to my other point, with 60k on the clock the suspension on my car is far from fresh so i'm taking the blanket approach plus with a new family (Be warned nappies are not cheap!) i'll be keeping this car until it or I keels over!!
However to answer your question specifically the front and rear H&R ARBs were £289 from DPM which for the authentic warrantied product with the genuine bushes is about the going price (be warned also anyone else reading this there are an awful lot of cheap returns and fiddled packages out there)
As i'm getting to know my way round the Audi mod market i'll obviously see ways like you describe for creating a better car at a far cheaper price than i've paid for this, but its my old mind set i suppose. If i can afford (just!!) to put in 'peace of mind' products in the fundemental parts of a car that provide the most effective upgrades then i will.
Tyres then Suspension and then Brakes has always been my approach! - although i inadvertantly let the kid out of me and got the REVO first, ooops!!
If anyone can recommend me a decent place in locality to Northamptonshire for full suspension fitment and tune for less than
£600 plus VAT 
that'd be greater still(!)
Bubstar - that's one nice looking car btw, i'll post some before and after pictures here when its done.
