I was able to contact a local distributor in San Francisco;
1064 Revere Ave
San Francisco CA 94124 USA
P: 415 822 2041
Dave at Recommended Service put me in touch with Geoff the engineer at Ikon and we figured out this is what I needed;
7610-1282SP6 for the front (unless you do not want a new spring in which case it is just 7610-1282) and 7610-1638 for the rear. 7610-1638 normally comes with a spring fitted but if you wanted it made without new springs that could done but needs to be noted accordingly.
Cost wise 7610-1282 is AUD$175.00 while 7610-1282SP6 and 7610-1638 are AUD$210.00 each shock (ie $420.00 a pair).
Its like Christmas getting new shocks! BEAUTIFUL!
The only difference is that the nubs on the new ones that hold the height setting in place stick out a little more so they don't fit flush into the old fittings. I could have ground them down, but it doesn't seem like it matters.
The ride on the new shocks is amazing! No more creaky Twike'n! These shocks have 4 settings on them. There is a little # at the top of the eyelet. I don't think you can change it with them installed in the rear. 1 is the loosest, 4 for heavy loads. I kept all mine on 1.