PS: If you are so strongly want to use redirect - use Java , that will help your site to live longer.
Unique content isn't nesessary, Google eats everything. Try to get more backlinks to avoid supplemental index. For example, my software store is absolutely non-unique site.It lives less than 2 weeks and has more than 2500 indexed pages and about 30 of them are allready in main index. Yahoo shows about 70 backlinks, Google 1.
Thank you for advice soopoot, rep added. I think it's the best option to do new domain with .ca extention. The problem is that I have to develop it and do SEO from beginning like for brand new domain. You correctly say that I might lose my uk ratings with redirects as even in Canada my .co.uk domain is on the first page but not as high as in the UK. Probably, ideal option would be to get .com domain but it's taken and there's no website there. No clue how to get it though. I think I'll start with French version as it's definitely won't be duplicate content as it will be in French and then combine French and English versions for Canada (they speak both languages).
Eh, I think DP members meant that the op should create a .ca website with relevant pages on that .ca website and redirect those pages to the UK website. Not redirect the UK pages to the .ca domain - that would be ridiculous and of course it would affect the UK rankings.
If you want to keep your rankings in Google.co.uk and ALSO rank in Google.ca then do NOT 301 redirect your .co.uk domain. If you no longer want to target UK market at all then feel free to redirect. If you want to target both UK and Canadian markets then I would suggest you do one of two things: 1) Get a .com domain, host it in the US, leave geo targeting unset in Google's webmaster tools, and 301 redirect you .co.uk domain to the .com. More than likely your backlinks for the .co.uk domain are from other sites targeting the UK audience so you should continue to rank well there. Then start building links from sites with .ca TLDs who are targeting the Google.ca view of Google's index. OR 2) Leave the UK site alone. Get a .ca domain, host it in Canada, and build out an entirely new site with totally unique content. There is a third option if the UK and Canadian sites do not need to rank in Google.com. If you set the geo targeting for your UK site to UK, build a duplicate site (just copy it over) to a .ca domain, and set the geo targeting for the Canadian duplicate site to Canada, you'll be Okay. Because they are showing in two different views of Google's index, the whole duplicate content issue becomes a mute point. Those two sites would never be trying to rank for the same phrase in the same Google index... so there would be no filtering of duplicate results required on Google's part. If you have two duplicate sites both trying to rank at Google.com, and both of them "could" be shown on page 1, Google would typically filter out the one they consider to be duplicate... probably the one with the least amount of page rank (i.e. the one that has the fewest links or is on the least authoritative site). But because you have set the geo targeting for the UK site to UK and for the Canadian site to Canada, those pages are never going to be competing with one another so duplicate filtering becomes a non-issue. Matt Cutts has said this is even ok for the same site. I can have example.com/us/, example.com/ca/, example.com/in/ folders on my site that contain duplicate content targeting US, Canada, and India... And I can set the geo targeting at the folder level... simply add and verify example.com/us/, example.com/ca/, and example.com/in/ in WMT. Then you can set the geo targeting for these sub-sites, and they will not compete or get filtered because they are targeting 3 different views of Google's index - Google.com, Google.ca, and Google.co.in, respectively.
I see you guys frequently mentioning to host in Canada to get the best from google.ca Is it really so important to have a host in a same country as mainly targeted market?