First of all I use and recomend Ronstan Smart Ratchet - Part number RF42100...... You could also try Harken Ratchamatic part no. 363

As far as a spinnaker launching system goes..... I do not recomend the bag. Try either a sock style or a solid tube suffer system mounted on the spinnaker pole. You can set or drop these very quickly whilst running some hot angles. The bag has more potential for stuff ups and you have to run alot deeper to raise and set. While running deep you will be rolled by anybody near you running the pole mouted system. Also combine your tack line and halyard so you only have the one rope to pull up. The tail of this halyard should go back through the launcher and up to the kite (2 or 3 retreival points) to reteive the kite back into the launcher. This also tidies up the boat and you have no excess halyard on the boat.

See attached pic off the solid system that Bundock and Forbes use...... These systems can be made yourself or puchased from Marstrom, Nacra, Hobie