Being that I live in the U.S., I can't recommend a blood pressure monitor available in the U.K., except that there are a lot of them. One bit of advice, regardless of the brand/model you select, take it in to your health care provider and ask them to check it against their equipment. Most are reliable (until the batteries begin to run down) but it's important to assure they are reading close to the office machines.
Home cholesterol testing can be done at home, but it still requires a couple of drops of blood... not unlike diabetes testing. Again, allowing for the difference in countries of residence, here's one available here:
http://www.healthchecksystems.com/cholestrak.h tm ... Best of luck!