Russ did my previous GSA and I was very impressed with how the bike was protected and his workmanship
Full cost is £90 for the tank fitted (£45 materials. £45 labour)
Full bike is £180 (£90 materials, £90 labour). The full kit includes the tank, all painted surfaces in front of the tank, headlight, TFT screen, front forks, rear swinging arm and frame near the footrest where your boot normally rubs. I didn't need this last bit as the HP comes with plastic protectors so he gave me a discount.
I believe you can just choose the bits you want and it will be priced accordingly
Like you I would not be confident in fitting the kit myself. Russ is the expert and it still took him about 2 hours
His own GSA 1200 Rallye is in his workshop so you can see what it will look like before you buy
Hope this helps
Mike