You need an HMC (630mm or 800mm), not an HBM. An HBM is an absolutely massive machine... way bigger than you'd need. Most HBMs sit on custom foundations.The most important function I am looking at is horizontal boring (brown arrow higlight), diameter ~400 mm and length around 700 mm.
Is this your first foray into CNC machining? If so, this would be an extremely ambitious first project, to put it gently.