Hereford is
Maidenhead Aquatics - Fishkeeper but i dont know about prices, expensive, but the store i go to all the time is
Pets at Home - where pets come first
and my budget is hmmm £100 at the moment but at christmas maybe £300
this has got to be big nice light colourful big fish or something, scrap idea of live bearers, big colourful friendly tolerate other fish ok, good in a community tank
So you're changing the stocking list again?
Why?
You can't really do anything with 100 pounds. 300 pounds is a different story.
Do you have a stand for the 30 gallon tank? If not, factor that into the cost.
I think you're going to have to wait until Christmas for your budget to go up man.
Maidenhead doesn't have any aquarium/stand combos in your pricerange. I'd look at a cheap (40-50 pound) stand and a bare (15-20 pound) 30 gallon aquarium and a glass top. Buy them seperately or see if there is a combo with a cheap stand at some other store.
If you have a low budget, which you do, you should be looking online (is there craigslist in the UK?) for a used aquarium setup.
There's really nothing I can help you with now because you can't afford everything. You could probably find just the tank and the stand for 100 pounds. You'd still need a filter, a heater, glass top, striplight, substrate, driftwood, some rocks, plants, fish, food, and a large bucket for water changes.
Try to see if you can make some spare cash between now and Christmas. Maybe get a simple part time job? I don't know. Whatever you can do. Get as much cash together as you can, and then when you actually have a significant budget, we can do this.