Some thoughts (I'm sure many will disagree with these comments, they are just other things to consider, take them or leave them):
- Don't trust any motor that has been out for less than a year. Because of low volumes, customers end up being the manufacturer's product testers. Manufacturers cannot afford to have 100 engines on the test bench to see what the flaws really are. This has happened on most new motors, regardless of brand.
- Weight is not everything - frame strength also must be considered. If you are just starting out, get something built like a brick sh&^ house. You will save $$ on props and could also save yourself from nasty injuries.
- Repair-ability of frames. Most repairable to least repairable: stainless steel, good quality aluminium, titanium, carbon fibre, bad quality aluminum.
- Spares. Parajet, PAP, Blackhawk, Bailey, Nirvana are well established brands been around for 5+ years. Parajet is probably best availability in UK?
Could also consider the bailey hornet or Miniplane?
Sorry, probably confused your decision even more!