The F18 is not going to be that fast with your weight nor can you sail them single handed as the sail plan just is not designed to be that way inclined.

The Hurricane 5.9 although a big lump is not much heavier than the F18, is 2 ft longer to take the additional weight and at your weight can be sailed solo without the jib. The big plus they are a lot of boat for your money, have a very strong class which is getting larger ( its very competitive and yet there isn't the usual arms race which the F18's have gotten into )due to the boat being relatively easy to sail with the new sailplan that is now available.

The other thing is that although you will likely pay a little more than your 2K budget, you won't have any trouble selling it nor will you loose money as they seem to be rising in price at the moment.

The other boat you may wish to consider and there are plenty about in the UK is the Prindle 19, bang for bucks they are mega cheap and yet a Hurricane 5.9 clone.