I want to replace my existing drop bar and levers with an upright bar and brake lever that will work with the old side pull weinmann synmetric 733 brakes, that are long reach at 65mm according to Sheldon's measurements of caliper brakes. Am I right in assuming that long reach and long pull are two different things and the upright levers I need are standard pull?
Yep, 'reach' is how long the brake calipers are, and an indication of whether the brake pads will hit the rim properly.
'Pull' is basically how spongy your brake levers will feel. If this is not matched properly to the brake calipers, you could end up with jerky brakes that are very on-or-off and liable to catapult you over the handlebars, or ones that are just too soft for the job. Some manufacturers (modern ones?) specify which brake levers to use with their calipers, but inevitably they recommend their own ones. This doesn't mean that others won't work well, but that might be more a matter of trial and error and reading around.
I'm about to rebuild my front end (new brakes, new levers) and my best advice is buy from a website (or shop) that has a decent returns policy!
In a word, yes, you're correct in your assumption that "long reach" and "long pull" are different things.
At 65 mm your brakes might even qualify as "extra long reach." The reach of rim brakes is the distance from the mounting bolt to the rim.
Pull is the amount of cable that needs to be moved to get the brake shoes to clamp firmly against the rim. According to Sheldon Brown / Harris Cyclery, all caliper brakes use standard (short) pull levers.