I thought of another brand to consider (apart from the big names): it's FK.
I have yet to hear anything bad from 'em, even though it's not a specialist company. (Meaning, they make all sorts of tuning stuff) If anyone has experience with them, I'd apreciate your thoughts on them. Decent kits are the HighSport coilovers that forgo the adjustable damping of their bigger brother, the KonigSport.
If you're just after altering the rear height, in relation to the front, you *could* consider those spring/damper combos that have adjustable rear spring-seat-heights.
Still... I found that once you've been bitten by the Low Bug, there's nothing better than coilovers. Even if you want a moderate drop now, what about in 6 months? Or 12?
Perhaps FK's are an affordable and relatively good alternative. I can't judge the Weitec's, just don't know enough about them unfortunately.
About the hardness -
As Ash advised me a while ago, if the difference between hardness adjustable and non-hardness adjustables coilovers is small, (say - 100€?) get the hardness adjustables. It allows you to set them to 'hard' when you want to mess around and drive slammed for a while, and if you're done with that you can set them to comfortable again. Keep in mind that 'comfortable' is a relative term. It's still firm.
I just set mine to 'all the way open' for the winter season and it's definitely noticable. More bodyroll, somewhat less grip, but more forgiving.
There's other things to keep in mind too;
I chose the KW's over H&R (and everything else) in part by their stainless steel threading. I drive them all year round, and rust is something I could do without... If the threads start to rust under the adjuster ring, they're likely to seize.
Also, they had oil filled Koni shocks, which I like better than gas-filled items. I could be really wrong here, but I'm convinced oil filled shocks are forgiving (soft) on small bumps such as on bad roads, but are stiffer on long big dips, where there's a lot of weight on the shocks. My gas filled shocks I had before were the exact opposite - rock hard on small seams and bumps, but soft on big dips.
As a 'Final Thought' (remembering Jerry):
Your suspension is the most vital part of the car. Ok, brakes are up there as well. But it's what holds you on the road - it
needs to be good. I wouldn't buy anything other than Klaus Wohlfarth's gear ever again. Devotee for life.
