Most brokers offer demo accounts. The only differences would be that certain aspects like the spread may differ based on the broker. I started trading on a demo with CedarFX on MT4 and switched to a live account later on. Never had any issues with the demo account, and support is online 24/7 so I suppose that could be helpful if you needed any assistance.
I suppose traders shouldn't choose brokers according to thia criteria. You know that demo account matters only in case if you need to elaborate a special strategy for your trading activity or edit it. Moreover, it's a good wy to practice if you're a rookie in trading and you're still learning fundamental things in it. Brokers always offer similar conditions on trading on demo account becaise it doesn't matter, everything you should have on demo is a good sum of virtual money in order to train your skills and no more. It's enough for you to trade on demo actually. Brokers should be chosen by other more vital criterias.