I would use blast from NCBI (https://blast.ncbi.nlm.nih.gov/Blast.cgi) on a database of cDNAs. However, if I were interested in the protein product I would use protein sequences and not cDNAs because the latter tend to be more divergent than the former.
you can also use the blast from the UCSC (http://genome.ucsc.edu/cgi-bin/hgBlat) where in addition to the data you'll have a useful genome browser with lot of optional tracks (you can apply your own custom track also).