30" long is huge, AB!
I bought a Creworks brand 6L (6 liter) size off eBay about a year and a half ago for around $100 that I use for my motorcycle stuff - mostly brake and carb stuff - that does the job for me.
It only has a 12" tank length.
Even their
30L size only has a 20" tank length.
Others here will add input, I'm sure.
Good luck!