Personally I'm thinking about using a paper wallet to store my coins and wait some days in August to see what happens, upgrade my wallets, let others report eventual bugs, etc.
Lets say that btc is £2000 and there is a split 80/20. It stands to reason that the value would be roughly £1600ish/£400ish = £2000.
Lets say you have one btc. After the split you will have 2 "btc." Total value of 2 "btc" = 1*£1600ish/1*£400ish = £2000.
The idea that after the split the value jumps higher than £2000, without any new money coming in, is preposterous.
One can sell their btc for £2000 and wait as the drama unfurl itself. If one thinks that £1600 coin is the winner and the £400 coin will fade into nothingness, one can spend £2000 buying 1.25btc @ £1600 and profit from this drama.
What we're talking about here is how to safely live through the possibility of a fork.
What you're talking about is taking a huge gamble that could cost you everything.
Yes it's a way to do things, but not comparable at all.
As for the others talking about selling everything, do you think early BTC adopters that are still around did this ? No, they held, and they were right to.
Nope. btc already fallen over $500 since i last sold some bitcoin. No gamble at all.
I was mainly thinking about the other part of your plan, buying only one of the forked coins. Obviously if you stay out of it you can only lose "potential gains". Which could still be huge, I can see BTC rising a lot very quickly if all goes well.