re" Adsach, was the m030 option available for 03 S's? "
m030 has been a number for factory tuned suspension since long before the Boxster. It has been used on the 911/964/993/996 and I suppose on the 92x/94x cars as well. Probably the only Porsches that don't have the m030 option are GT2, Carrera GT, etc(think of it as standard).
For the Boxster the m030 springs are progressive so that they are both a little softer during the first 1/2 inch of travel and firmer during harder bumps.
The ROW(Rest Of the World) 030 is about 1/2 inch lower than US all around. Lowering is a help for serious cornering as it allows one to dial in more front and rear negative camber in a 4-wheel alignment. This is helpful to the Boxster as it is camber challenged (I max out at -0.8 front, -2.0 rear - my wifes BMW came fixed from the factory at about -2.8 rear). Because of the lowering folks who add 030 in this country usually purchase the ROW030 springs.
H&R and a handful of other companies make respectable lowering springs.
The most popular suspension upgrade in the last several months has been Bilstein PSS9 - though folks complain about the lack of adjustable rebound damping, the results of folks who have installed them has generally been very positive.
If you are serious about suspension and other performance upgrades, you might want to make it a habit to monitor the Boxster Racing Board. These are real drivers who give real opinions on the mods they have done- often with DYNO and lap numbers.
http://www.iq.dynip.com/~racing/index.cgi/index.cgi?