Hi Emmdee
I'm glad to hear you are getting back into the hobby. Our member Helen also has young children and can help you with that aspect
And we also have members in Scotland, though I'm not sure which part.
Red spot light bars (as you are aware) do have ballast problems. If you don't mind the expense you should be able to buy a new light bar, though it may come with different fittings from the bar you have now. If my maths are correct, you bought the tank around 2006, about the time I bought my Rio 125, and that had T8 fluorescent tubes. I know they changed
to T5 tubes a couple of years after I got my tank (High-Lite bars) and I think they've now moved on to LEDs. You can still buy T5 High-Lite bars from various on-line shops at ~£100, and there does appear to be the odd shop that still sells T8 bars.
As for fish, I know you had them together before but tiger barbs and gouramis are not a good idea. Tigers are nippy fish and they can't usually resist the long 'feelers' of a gourami. And gouramis are sedate fish that don't appreciate fast swimming fish like tiger barbs and danios.
I don't know if you used this website last time round but
Seriously Fish is the best site for looking up fish - their water needs, tank needs and compatibility with other fish. It is written by fish experts, unlike other sites which tend to be written by people who just keep fish.
You have plenty of time to decide which fish to keep this time round while you cycle the tank. There is a newer method for fishless cycling
https://forums.thinkfish.co.uk/fishtank-filtration-and-cycling/fishless-cycling-how-to-do-it/ which was designed to stop nitrite getting high enough to stall the cycle.
Or if you want lots of live plants, you won't need to cycle. Just set the tank up, plant it and wait a week or two to make sure the plants aren't about to die, then add fish slowly and test every day to make sure ammonia and nitrite are staying at zero.
Whichever you decide to do it will be a few weeks before the tank is ready for fish, plenty of time to decide on tank mates for the tiger barbs - or have just a tiger barb tank with several different colour morphs