Hi Tony (Hi Dave),
Firstly I would like to welcome you to our group and, hopefuly, to the Liverpool Astronomical Society.
Purchasing a telescope is something that takes a lot of thought as once you have paid your money you may find that your set up does not do what you want or after a short while you outgrow it and wish that you had saved the money and bought the next model up.
The problem with this hobby, like any other, is that you get what you pay for (blunt , sorry !) and whilst you may pay £200 pound for a reasonable set of optics you find that the mount lets the side down. If we magnify a planet X100 then we also magnify the wobble and bounce of the mount by the same amount. So, I suggest that care should be taken to select a good solid mount that will track your objects and keep them in the centre of your field of view.
A large mirror or lens will allow you to collect more light , detect fainter stars and galaxies whilst resolving finer detail on the planets, Moon etc.
A short focal length will be more forgiving on a ‘cheaper’ mount and would give larger fields of view. The downside would be that you would not get good ‘zoomed in’ views of the Moon and planets.
For lunar and planetary work you would need to think of the longer focal length scope and mount with good tracking. A large aperture is prefered to get the fine detail.
As you may know, there is no one telescope that does all and at some point a decission or compromise has to be met. The important thing is not to spend your money until you are sure that you have the right set up.
We are only touching on the basics of what may be suitable for your needs and I think that it would be much better if you could come along to the observatory on a Wednesday and we could chat further.
Regards from Dave Galvin.