I use avo coilys, and think they are ace, have used most makes as well over the years, I have on more than one occasion got comments from rear seat passengers that this was the most comfy cossie they had been in, opposite locks friend also commented to this effect.
The spring rates may not be to everybodys liking but these are easily changed, indeed avo will exchange the springs once for free on new sets if you don't like the rates, I use 300lb 9" front and 200lb 12" rear.
From your description I think you have more than suspension issues.
The biggest problem is the cossie is a pile of shit in the suspension department at the rear, it's quite laughable for this sort of car, or bloody dangerous if looked at another way!!
They might just as well fitted the beam on with bungee ties, would have worked just as well.
Stability can be improved 100000% with a poly diff mount and a 22mm arb on the rear.
tabetha