I have a 5 foot box blade from Tractor Supply and my Deere 2320 (same as your 2025R) pulls it just fine. With ALL the ripper shanks down, it sometimes bogs down a bit, but for 99.9% of what I use the blade for, a 5 foot one works perfectly. I have a 6' landscape rake and it works well, but it's a totally different implement with less HP requirements. I think 6' might be a bit too much for the 2025R in a box blade.
As far as the Tractor Supply "County Line" brand goes -- it's been a great tool, with no issues. Well constructed and sturdy despite a lot of abuse. For a 25HP tractor, it's constructed well enough that you won't destroy it. Just check the units at the store and buy one with good welds and no rust (since they usually are stored outside.) For half the $$ of what Deere wanted for a blade, I'm 100% satisfied with my TS CL brand blade.