Yes please mate My loft is hot as shit atm and I think in the summer just going to get hotter with a 600w hps as well. I don’t mind diy opinion I’ll give it a go
First thing I have to ask is price range... the options are huge for DIY and the rabbit hole can go deep but what ever you build will be near half the price of the top of the range pre built units with the same parts.
ha ha keeping a loft grow cool/warm is one of my super powers, I grow in one too... Where do you draw your intake air from ?