WalMart generally carries the reliOn brand and I know there is a 30 mL (cc - same thing) version with the half-unit markings, a 30 or 31 gauge needle which is 5/16" long. You might call in advance to ask them if they have them in stock, and if not, to order some.
If you have a sturdy ruler with millimeter markings, you may be able to use that to get a consistent amount out of the U-40 syringes by always lining up a specific ruler marking to a specific syringe marking, then placing a mark on the syringe for the amount you want to draw. Not perfect, but a tad more consistent than just eyeballing.