I am looking for information on screening Vegetables such as Brocoli,
Coliflower and Spinach etc. which are known to be highly infested
vegetables.

What I need is information on technology to screen and analyze these
Vegetables to check if they are infested.  It could be done through
Nuclear Magnetic Resonance Analysis (MNR) or ESR Electron-spin
Resonance (ESR) through checking the Vegetable for the protien which
is fould only in insects or check the Vegetable for Chitin (a plyymer
found in shells of insects).

Any other ideas of how and where to do this.

I would like to know of labs that could do this for me or if I could
do this myself with some equipment.

I suggest you do research via the National Agricultural Library www.nal.usda.gov

jlapminy-ga
    
The following are a two contacts that you could make to check about
the validity of screening your
vegetables.  

Roger Ruan - U Minn - http://rabbit.bae.umn.edu/~rruan
Micheal McCarthy - U California - Davis  -
http://foodscience.ucdavis.edu/mccarthy/index.html

I doubt you would have the magnetic field homogeneity to process
spectra from your vegetables.
Image based detection is your best chance.  The above two labs may be
interested in the problem but you would find it difficult and
expensive to assemble the equipment to perform these tests.