You should be able to source appropriate Shimano or Suntour front and rear mechanisms for sensible money and wheels too.
Ditto gear levers.
Just make sure your rear wheel is suitable for the width of the frame - measure between the rear dropouts (slots where the axle goes), which determines the wheel/hub width - I guess it'll be either 120mm or 125mm.
Weinmann brakes would be fine, they're good brakes but aren't regarded as"sexy"so are easily and cheaply bought - many vintage bike components are overlooked because of snobbery.
Have a trawl through ebay to get some ideas, then put a wants ad on here - there will be plenty of help.
Co-founder of a V-CC section, member South Eastern Road Club and owner of - 2005 Bianchi Reparto Corse (modern), 1985 Raleigh SBDU Pro Super, 1984 Raleigh LU Corsa, 1980 Allin Stan Butler Special, 1978 Ron Cooper, 1975 Bill Philbrook tourer, 2 x very early Roberts (mid/late 1960s), 1966 Raleigh Superbe Roadster, 1964 Allin Stan Butler Special Belgique, 1951 Hobbs of Barbican S/C, 1950 Hobbs of Barbican S/C, 1947 Hetchins Super Special, 1908 Centaur Featherweight. 1988 Specialized Stumpjumper.