"allows 400 Watts ERP on 80 metres and top band"
Ouch.
My sympathy... I was feeling grumpy about our power limits, but it looks like yours would make some modes a *lot* harder.
I sure hope you meant PEP and not ERP, given that a good antenna will give you more than 25 DBi gain in ERP.
Can you do things like meteor scatter or EME on 400 watts? I'm guessing yes, but with more difficulty, but I suppose your local noise environment will also be an issue.