Cruising chute for an e 27

Hello, Was looking into buying a used asymetrical spinnaker on ebay from a catalina 25, price $500, My boat has only a 150 genoa and a main, no spinnaker in the inventory. This is the first year with the boat, and I am under the impression that a spinnaker would be essential here on the hudson river where the wind flows in such a manner that you may be able to run for a very very long time. The rig dimensions aren't in my opinion too far off I ='s 30' on the catalina vs 32.5 on the 27, Anybody think this will be a reasonable purchase given the sail condition is excellent? Thanx

and the J is??

A bit time constrained, so I was too lazy to look up the J on the Catalina, but the size of the sail is defined by the I and J. My guess is the sail will be significantly smaller than it could be. If the J's are very close to each other, then the foot and LP will be similar and you will just be a couple of feet short on the hoist...

My advice is to find something within 5% of both your I and J...
Cheers,
S