I've decided to buy a gigbag for my tuba, because it'll possibly be cheaper than having to take the car into town every week

The problem is: my tuba is a 3/4 BBb, and I've looked all over to find a reasonably priced bag which fits the horn. The bell is 18'', and the instrument is 43'' high. Bags I can find are either for 18'' bell but too short, or high enough but for a 22'' bell.
Does anyone have advice on whether I can safely use the 22'' model, or an address where I can get a gigbag with the right dimensions at a reasonable price? (and willing to ship to Europe....)