Does anyone have any recommendations for what to buy?
I suspect it would be
better to get a higher quality used one than a cheaper new one. Perhaps
I would normally go along with that, on the grounds that an old 50MHz
'socpe (say), correctly maintained, is till a 50MHz 'scope and is
preferable to a modern 20MHz 'socpe.
But...
While an older 'socpe is likely to be much easier to repair than a modern
one (fewer custom parts, etc) and will probably have much better
documetation (the manuals for older Tektronics 'scopes in particular are
absolutley excellent), it will prboably fial more often than a brand new
'scxope. Taht said, my experiece is that older good 'scope are still very
reliable, but yuou may find you have to do the odd repair from time to time.
-tony