I have lived in Scotland too long to be able to justify spending money on two pairs of waders
...so I bought one, that does both roles, as chest and waist waders
I bring you the Orvis Silver Sonic convertible waders, currently on offer
I have had mine around 5-6 years and they have been perfect.
When walking along the bank in the summer, I have them as waist waders, On arriving at a deeper pool, up they go, bingo, chesties. They have been a god send this summer and saved sweating buckets into my waders. Also good when shooting the breeze on the river bank or in a boat.
They really are a very nifty bit of kit!