Your best bet is.....a mortgage!

You will not be able to borrow the amount of money that you will likely need to pay it off for anywhere near the same a rates as available through a mortgage. The best personal loan rates would proably be around 8% where as a 90% LTV mortgage rate (high rate) would be around 5%

If your mortgage rate is high then I would suggest that you speak to a mortgage brokers about looking for a product that may be cheaper for you. if you are looking for a longer term on your mortgage there are many lenders that will allow you to borrow through to age 75 if you can evidence that you have income in retirement. Other than that you may be restricted to borrowing till age 65 (retirement age) although there are now a couple of lenders that will allow you to borrow through to age 70 without proof of pension so long as the work that you are doing is not too physical or strsssful for a 70 year old to do. In other words, they would not expect you to be playing professional rubgy at age 70