Yeah you'll have to get in those races and upgrade! Most all of the ECCC races will count so I'm sure you're close by now. The C training race will definitely be slower than the collegiate Cs.
I think generally the ECCC collegiate Cs are a just a little slower than a full 100-man cat 4 field. Of course the competition in collegiate is more uniform and in cat 4 you (if you're strong) will end up really racing against the top 25% or so. These training races vary though, usually depending on whether or not there is a real race the same day. Either way you're probably fast enough for the B(cat3/4) race at Wells, but worse comes to worse you win the C!