WAIT.

There would be lot chaos after implementation of UASF if it gets implemented without SegWit2x and there would be a price dip (could be slightly long term) which can even go to 30-40%. If Segwit2x gets implemented before the implementation of UASF. Dip would still be there but would be for short term. In both the cases you will have a good opportunity to buy bitcoin.

At present invest in any top 5 altcoin. They would definitely rise in August because of devaluation of bitcoin. Earn some profit from there and then buy bitcoin in August at lower price.