The main problem with the DIY coilovers are that you can't go much lower than standard lowering springs for one reason, you aren't using shorter shocks/struts so they will just be on the bumpstops as you run out of travel against the top of the shock body. I know as I've done this several times

. The rear are easy to do, replace the pig tails with very short and high rate 2.25" coilover springs.
The best way to do it is using shortened shocks from a Corrado G60 or E30 IX, get the strut housings shortened and then use the DIY coilover kit. But you need to know what you are doing... When you've done this, bought shocks, bought springs, paid someone to do the welding if you can't - then a set of Gaz or BCs don't seem that expensive anymore.