You're perfectly safe and legal to tow, even with the Saxo, have a thorough read on the www.gov.uk
website - it's even got information on safe towing. Just make sure the MAM of your trailer is under 750kg.
I drive a 1.4L Fiesta which has a rated tow capacity of 900kgs and I've towed several different trailers and weights with it no problems.
My towbar was £30 second hand off eBay, fitted myself in about 30 mins, had it checked and wired in by a mobile fitter for an extra £15.
If you're planning on launching with it, it's worth practising reversing in an empty car park, for me when I started it was just towing in a straight line - so I've only recently had to practice reversing!
I'd recommend letting the insurance company know you're towing as well. There's no increase in premium or excess, but it's safer they have it on file.