No need to change the fuel regulator or the fuel pressure if you are running a standalone computer Mike, you can just change the injector size in the standalone. If you start messing with the fuel pressure you are actually getting less volume out of your pump. (volume and pressure on the pump side are inversely related, while volume and pressure on the injector size are proportionally related)
I do not have a part number for the injectors sorry. We did not get the fourth generation 3S-GTE here in the US, but it is a common swap in MR2's so the shop I used had many half cuts but the funny thing is the MR2 guys all went to the 1000cc injectors so he had a whole box full of the 3S-GTE injectors that were left over. I put a pic up many pages back I will go back and see if I can find it.
Yeah I started my LX450 and I swore I was not going to spend any money on it, I was just going to do the PM and drive it. Well we all know how that goes. lol. I too am at about 1300m and travel a lot between 2000-2500m, the turbo makes all the difference in the world.