Go for the full cage.
I know Ionics seem expensive but if you can stretch to it, go for one of theirs.
Crash tested. Your life may depend on it the worst happens.
gardiners are also crash tested and quite a bit cheaper also I think brodex do.
Then straps are made for the tank you have, I would go for a FULL CAGE, BUT THEY WOULD NOT BE ABLE TO SELL THE METAL STRAPS IF THEY WERE NOT FIT FOR PURPOSE.
you can have a frame made at a welders, or try purefreedom.co.uk they make tank frames and systems.
it is down to you and what you want.
Ian