You ought to be able to get a Calmet 400 or Graphic View for $200 which will do anything you'll likely want a 4x5 monorail to do (and the Graphic View lools like it was made to sit upon a Tiltall!)
Maybe another $200 for a lens.
Most people like Toyo loupes, used they can be found for $30 or so.
Ask someone in your family who sews to make you a dark cloth.
Whatever light meter you're currently using would work just fine unless you're into the Zone System where spotmeters rule.I don't know what those are going for these days.
$50 should get you a nice stack of film holders.