Yep, Jailhouse Blues (JB's) is the only mod to reduce actuation point (It works on greens too). It raises it .8mm (2mm to to about 1.2mm best I can measure).
Otherwise, you should look into ALPS or scissor switch keyboards, however, JB's probably have the highest actuation point of any switch on the market.
Using stock caps, o-rings work fine, SP caps however lack the ribbing to hold the O-rings. People have been looking for solutions for a while. The "rubber ball" mod is probably the cheapest, but also the most work, but if you are in the switch already, it's not a big deal. My personal solution was to shove 2 o-rings under each cap. This isn't exactly a cheap solution as you need 2 sets of o-rings to do an entire keyboard. For the moment, I only have the letter keys done. My total travel is only 2.3mm compared to stock Cherry MX at 4mm.