A very close friend of the family completed a chemo course last year Wayne, she spent around a year through the treatment wearing wigs (quite expensive but very convincing - apart from her bright blue one...) but after chemo finished her hair started to grow back very quickly. It's very curly and very fine - almost like a childs early growth I'd say as a comparison - but gradually going back to how it was originally. It's not patchy and she's over the moon after having similar tales of doom before her treatment.
No two cases will be alike I guess but in my limited experience I'd wait until after the treatment before making rash decisions involving thousands of pounds. I think personally I'd be a bit worried that an implant system could interfere with any natural regrowth afterwards.