30 to 34° nails are all clipped head ("D"-head) or offset head nails, paper collated. Full head nails are always 20 to 22° and can be either plastic or wire collated. AFAIK the only people doing 30 to 34° offset head nails at present are Passlode (their patent, I think) - and of course they only seem to come with the gas
As there seems to be some confusion about what nails you need it might be a help if you could state the gun you are using, then someone can point you at the correct type of nail and an appropriate supplier. I own pneumatic, cordless and gas 1st fix nailers - mostly clipped head types, but also a couple of full head guns
As it happens for clipped head nails (30 to 34° paper collated) Selco are pretty good - they (used to?) carry Rawl, a decent enough brand. They are also cheaper than Screwfix or Toolstation. Full head nails are a bit more awkward to source (we buy our nails in bulk through a trade outlet, normally 50 to 100k nails at a time in the early stages of a project - buy 500k or more and they throw in the guns for free, not that I ever see any many). Just avoid cheap or unknown brand nails (e.g Champion) as they are more trouble than they are worth