UK postgraduate studies dilemma

[Bemanos]

Hello everyone, i have a dilemma. I have been accepted to a fully funded PhD program ( stipend+tuition for 4 years) at Heriot-Watt Uni in Scotland, but i have also been accepted for a MRes at Imperial College (1 year). The problem is that for the MRes i dont really have any funding so i will have to resort to loans in order to attend. This will leave me with aprox $20k in debt by the time i finish. I am Eligible for a EU loan for graduate studies which has low interest rates and very flexible repay plans, so i could be debt free in a year or two after graduation, providing that i can get a decent job.
The Idea is that by attending to Imperial i will have better chances to be accepted at a top School for PhD later, but people keep telling me that i should go to the program in Scotland so i wont waste time/money with the MRes. (Note that both programs are in Chemistry)
Any advice is welcome!