I dont think I've used anything other than a sash cramp in most jobs, though in the house 9ive a number of these 'quick clamps' ranging from lightweight Irwin ones(blue) at about 400mm, and a couple of the original(yellow) at 600,, and also a couple of the 5' original (yellow)
The quick clamps I've found are best for holding something to a bench for say routing, but for gluing up its sash only.
Quick clamps you can find everywhere and i dont think it matters whether they are Bessey, or Irwin, or the originals, just so long as its not the cheapo pound shop type as they slip and are fit only for the bin.
On the sash cramp front,there is 2 types, 1 is a straight flat bar, the other is a T section. The straight bar are best for 90% of jobs, unless you're gluing up huge oak gates and you need that extra strength to force in those M&T joints, and they're good because you can easily join 2 cramps together to make them long enough if the job calls for something longer than normal.
Prices on the flat bar be that Axminster or Irwin Record is about the same, but you should be able to find some similar on places like Ebay for a bit less, and also 2nd hand on Ebay
Rutlands have a good deal of a pack of 6x1200mm sash for £130
https://www.rutlands.com/products/s...MI7_6WodSwigMVszsGAB1PdTCpEAQYBSABEgL0CPD_BwE