>>3734556I would get a Mamiya 645E, the glass is super sharp and hit has a built in meter. I bought mine for $350 with the 80mm 2.8.
If you had more to spend I'd say to go for a hasselblad 500cm since it's a bit more durable and the WLF is really nice to use for portraits. Plus if you get tired of it you can easily sell it for what you bought it for. But as far as optical quality, you won't be missing anything with the Mamiya.