I tried the Life Technologies microscale labeling kit (Alexafluor 488) for green fluorescent labeling of a soluble receptor antagonist. I used successfully the labeled receptor antagonist in a lot of fluorescence microscopy experiments. It is easy and fast to use, a little bit expensive but for me it worth the price.

Life Technologies also sell antibody-labeling specific kits for fast conjugation of antibodies with DyLight fluorophores. https://www.lifetechnologies.com/order/catalog/product/53025?CID=search-product

I hope this could be helful. 

MarkerGene has some as well: 

http://www.markergene.com/index.php/marker-gene-trade-kits/labeling-kits/markergene-trade-fitc-antibody-labeling-kit.html

http://www.markergene.com/index.php/marker-gene-trade-kits/labeling-kits/markergene-trade-tamra-antibody-protein-cell-labeling-kit.html

Thank you for your replies. Am checking out both websites for details.

Our group has had good luck fluorescent-labeling antibodies for flow cytometry and other applications using this protocol (just published in Journal of Immunological Methods), basically you label, wash, elute and concentrate your antibody all in the same centrifugal device:  Cappione A et al., Optimized small molecule antibody labeling efficiency through continuous flow centrifugal diafiltration, Journal of Immunological Methods (2015). Give it a try!

http://www.sciencedirect.com/science/article/pii/S002217591500068X