I know where you are at. Analysis paralysis. I am in the same place for Crypto trading right now - LOL, and to make matters worse, I have just closed my Forex account that I opened Aug2019 without a single trade. But this is fourth time around for me, so I am being very patient.
What seems important now may not seem that important in the future, but have you compared these 5 against each other across a number of criteria that are important to you? You may not know where to start but a few spring to mind.
Customer satisfaction - independent rating?
Fixed or variable fees? Value of fees - expressed in PIPs or in % of trade value?
Slippage? Does broker act as counterparty to your trades, and therefore have slippage in PIPs, or do they trade through to a larger broker or direct to market?
How long have they been in existence, and what is the total volume of Forex throughput (though this number can easily be “created” just to appear bigger than they are.
I know IG Index is probably the oldest, and Oanda is one of the most frequently advertised, but am not familiar with the others.
Do you have any colleagues who already trade and would it be easier to use same broker as them if you are looking for initial advice from friends
Do any of them appear in the top 10 of any “best of” surveys, and have they been paid by broker to say so?
Best of luck choosing, and it’s not the end of the world if you want to change your mind in a month.