I spoke with roberts last time I was getting a refill, you have to have a decent amount, 500+lbs before a packard is required, and 1500lbs before a CDL hazmat is needed.

So if your just going to get a 120-150 nitrogen tank you can transport for personal use without an issue. Personally, I agree storage and transport should always be upright, even if you have to build a little wooden rig like I did to bring my tanks up to exchange.