I can't find my invoice to give you the part number. What I did though was bring in my OEM struts and they matched them up as best they could. The OEM struts had no markings on them so it was a bit of trial-and-error to set the correct amount of gas. I think the guy lost a bit of patience by the end, as he overshot and the force required to close the boot is a bit high - at least there's zero chance of it accidentally closing on me. I had to secure one end of the struts with an E-clip. Ended up costing me $77 for the struts, plus a pack of E-clips from Bunnings. Lexus of Perth wanted over $150 to re-gas the OEM struts.
For $60, I reckon Danny's used IS 350 struts are a good hassle-free option.