Thanks Chuckie. I've read some nice things about Bisons, but I just wondered about these Buchanan ones. I've seen a good deal on them - or is it? That's the question!
This is for a spare pair, but they look pretty good.
A bit more info:

Breathable 4 Layer Fabric
Outshell: 70D Nylon Taslon +
DWR; Thorn resistant
Lamination: Polyurethane
Coated & Film Laminated
Tricot: Nylon Tricot of
6.6 Nylon
W/P :10,000mm/H2 O
M.V.T :4,000g/mē//24hrs
Color: Olive
* Articulated knee reinforcement
* H style detachable suspender with quick release buckle(socket accepts
plug at oblique angles)
* Multi-function exterior pockets are ideal for carrying lines & flies
* Front chest hand warmer pocket, interior Velcro pocket
* Build-in gravel guard with brass hook
* 3.5mm neoprene stocking foot with high-density neoprene sole
* High front and back with draw cord tighten around chest
* Fully taped seams
* Lightweight, breathable fabric keeps you dry and comfortable
B reathable waders have totally changed life for fisherman. However hot the weather you should wade and walk in total comfort. Even in the cold months you can still use them over a set of base-layer thermal
In the past, reliability and efficiency in breathables has come at a big price. Not now. These are real quality breathables at a fantastic price. The fabric is waterproof to a hydrostatic pressure of 10,000mm/H2O and breathable to 4,000 g/mē/24hr. In normal speak, this means that you can deep-wade with complete security and you can walk miles in a heat wave! The four-layer construction gives extreme ruggedness with hardly any weight.
The design is equally impressive: a removable shoulder strap with low-profile opposing buckles allows rapid conversion to waist-high use. Other features include an internal security pocket with key clip, an external gear pocket with a Velcro seal and an external micro-fleece lined hand-warmer pocket for those colder days. Also provided are the built-in, elasticated gravel guards that keep the neoprene foot safe from damage.