I have begun to shop around. I have hours in the Janus Puchaz K13 K21 K7 and Bocian
No single-seater hours, so definitely talk to your CFI. He or she will assuredly have views on what's appropriate as a next step.
Bear in mind that gliders don't sell like cars -it might take months or more to sell one if you decide that it doesn't suit you. A season flying your club's single seater(s) might be a good investment. (a) It will help you discover what you want in your own glider, and (b) the experience will help convince your CFI that you'll be safe in whatever you finally decide to buy.
I'm guessing you have around £10k to invest, so not enough for a 2nd generation glass glider. The first generation have a much wider range of handling characteristics. I'd predict that most CFIs would consider, say, an Astir as fine for a first single-seater, but might have concerns about a Standard Cirrus or a Libelle. With a season in single seaters, if you're competent, the range of acceptable gliders would be bigger.