If given the option I would do the 5-year course. For two main reasons:
1) you will more than likely get to experience more than one sector of pharmacy as part of your prereg year. while many hospitals and independant community pharmacies give you 2-4 weeks experience of the other sector, the 5-year course should give you 6-months in each.
2) integrating the preregistration year into the degree would have helped me put my class-based-learning into practice much sooner. It wasn't until the prereg year that i started to make links between pharmacology, therapeutics, evidence based medicine, pharmaceutics, and the patient. I beleive doing more practice earlier, and applying your knowledge earlier, will make you a much better pharmacist.
However, I do understand where you're coming from with regards to costs. It doesn't state whether you get paid for your 6-month prereg blocks and that is worrying, especially considering the 75% fees payable. If students don't get paid for these blocks then they will end up paying up to £4,500 more than current students. Not Good.