Hi Adam,
Thank you for your message. With regards to fitting spacers, because the wheels are further from the hub, more stress (lever action) is placed on the wheel bearings, potentially causing them to fail prematurely. Notwithstanding this there are many reputable companies offering suitable conversions. However, these issues can become involved so my suggestion is, that research is undertaken (the internet contains a lot of reference material) and professional advice is sought whilst seeking the right solution.
Regards,
Paul