Never sign any documents until you have read every word and understand what you are signing. Get your S&P lawyer to explain whatever you do not understand... that's why you are paying your lawyer. He has an obligation to explain until you are clear on everything.

Also raising the S&P to 230k is a bad idea. As minolta pointed out, you'll end up paying more for the stamp duty and legal fees because the duty and legal fees are calculated as a % of the purchase price in the S&P.