I would plan to both matey, neither of these options will provide any guarantee of getting a job. Instruction is good fun and a valuable experience but the pay is crap and it will take you a couple of years to get a 1000 hours. Alternatively a TR will cost £15k - £20k and give you one hour on type. If you dont get a job having done the TR what will you do then? Whatever you decide to do, get the ball rolling ASAP as you are slipping out of the best window of opportunity at your age.
cheers
MJR