I usually just buy whichever ham is on offer. As long as it is lean (no visible fat) it's FREE.
I often get Weight Watchers ham, or Morrisons' own - you don't have to stick to one brand.
If it is in a packet check the list of ingredients. I picked up what I thought was sliced chicken breast in Tesco the other day and found it was "reformed" and contained such things as pea starch and some other things I didn't recognise. I put it straight back!