Jspec only has one sensor, UK spec has 2. I and melonman on here use the DOX-0228 in our Jspec's
To be honest the only difference between the models I reckon is the fitting components supplied with the sensor and plug to connect it to the loom. All the Sensors are the same just the fittings distinguish each model from the other. I was talking to Marty and colin to up in SSI , they said the same
Logically if you think about it, Denso make the Lamda sensor for Toyota. This is a denso sensor, how many ways can you read the O2 levels. If you are driving a toyota Corolla or a supra I guarentee all the denso sensors are the same. I think whjat you need to avoid is other manufactures like Bosch, if you stick to denso or OEM which is made by Denso only difference is toyota's mark up