Ian,
I would consilodate what you have done.
Take a few trips with an instructor and get even more profficient than you are now. Get him to show you some of the pitfalls.
Start going off by yourself, a bit further each time. Learn your local area.
Plenty of time to do a night rating, enjoy what you have got now, and think about a night ticket after a few more hours, when you are really up-to-speed with everything else, and you are absolutely comfortable with the aircraft.
Remember, walk and trot before you start to run.
Well done again
TSM