I had asked if there was a plan for there to be a program to design the mechs, and since there isn't I have been spending some free time here and there to throw together a little prototype (really a little proof of concept so I can start planning the real thing).
http://epic-enkidu.com/drome/
It's fairly crude, not a whole lot of validation and the ones that are in there don't exactly work right. But if you aren't trying to break it you can make just about any light mech currently! Except for that extra hardpoint advantage...
Hopefully by the time the mechs start shipping I'll have a decent looking form and Printable mech sheet running off a database and with real data validation!