In clamping up a case one usually uses clamps in sets of 4. Lots of panels are of a length that 3 to 4 clamps are needed per panel. Panels are rarely over 2' wide. Cases are often 3' in some direction and occasionally more.
With that in mind an unlimited budget should buy 4- 2', 2- 3' and 2- 4'. This set will do almost everything you will ever need to do. If you glue a lot of panels at one time, add more 2' clamps. I have 8 for example. Occasionally you may use 4-3' and on rare occasions I have needed 2 6'.
Actually, I think you are about right. I have 6 of each, 2' and 3', but I seldom use them all. When I run out of 2' ones I press the 3' ones into service. So if I had fewer I would still be OK. And you can sequence the work, instead of preparing a batch of panels or whatever, prepare one and glue it and prepare another while the glue sets. Glue that one and prepare a third. By the time the third one is ready you may be able to use the clamps from the first one, specially if there is lunch or a nap involved. I like to leave them in the clamps for several hours or overnight if possible but in some cases I have removed the clamps in thirty minutes or less. Titebond says not to stress the joint for 24 hours (?) but I have never had one fail after 30 minutes. I run them through the planer or sand them and cut dovetails in them and they have been fine.
I am talking about my Dubuque Aluminum bar clamps. I added them to my Hodge podge collection several years go and they are a joy to use, but I kept my pipe clamps and they get called up on the rare occasion I need longer clamps or more clamps.
Maybe I will treat myself to a few four footers. Christmas is coming. Off to sand the panels for a toy box.
While I don't like to use them, because the clamp pads are so short and black iron will stain wood if in contact with squeezeout (I know, should be just drops, but sometimes "should" forgets to step forward), years ago I needed to clamp an eleven or twelve foot length. Stepped up to 3/4" pipe clamps, several lengths of pipe threaded at both ends, and some unions so I could join lengths of pipe between the clamp ends.
Unlike you Bill, I really like my Bessy K-body clamps. I have up to 5' lengths with couplers so can span 10 foot!
Over the years I have went to many auctions so have a very large supply of many various type clamps. A bucket full of pipe clamps, C-clamps, Jorgenson's, Wooden F? style clamps (up to 24"), etc.. Often clamps were dirt cheap at these estate auctions.
One reason I like the Bessy's is that I can set them on a bench - opening face up - lay in a panel and clamp then apply the upper clamps and the panel is held flat. I do use wax paper on the top of the clamp bars to prevent any glue getting on the ratcheting notches. Learned that the hard way years ago!
Bessy's have the best guarantee I could ask for. I had a couple of the clamp faces crack on some clamps I had had for several years. Talked to a rep and he sent me brand new clamps free and told me to keep the old ones.