ASW Helix 150 suspension

[bombomb]

Ive just joined this site i have a asw helix 150 performance coil. uni filter, iridium spark plug, 130 jet. But back to the issue, i am going to replace the shocks and would like a larger shock but im just not quite sure what i need in relation to stiffness and length. From my measurements the stock shocks are 13 1/2" eye to eye, does this seem correct. i saw a helix on here, daveinmd was the user name and he has what looks like 2 inch longer shocks, i just want to make sure that i dont buy a shock that will be rock hard. Any suggestions will be appreciated.