Well there is a post on the freelander forum about fitting a turbo to a freelander here.
https://www.landyzone.co.uk/land-rover/freelander-1-8-turbo.268026/page-11
I'd keep working on your engine for now and learn from your mistakes before you tackle an engine conversion like turboing. There isn't a huge amount involved but it does need a bit of experience if your new to engine changes etc.