I used the standard low end Jabsco head from West Marine at US $199. or better on sale.

you have to redrill some mounting holes and I found that orienting it a tiny bit more so that it isn't facing too hard into the mast was a good step.

Other than having a porcelain toilet on board... toilet brand isn't on the list for an OD inspection as far as I have seen.

I have an Airhead composting head on the 2nd boat, expensive but worth it, plan to do the same mod to the J/30, no holding tank, no pumpouts, no smell!

Wow, a composting toilet. I never thought of that. Thanks for the info folks. I'm going to try and get the head replaced and holding tank issues solved before we go on vacation next week. So I'll be working on this quite soon.

Use the existing deck pump out as a vent by screwing a PVC elbow in to it, order the inline fan housing. With regular seasonal usage by 6 people the composting bin only needs to be recharged once per season. In the process you will get rid of the holding tank, diverter valve, macerator pump and overboard discharge seacock. Removing the discharge will require plugging the hole in the hull with epoxy.

What's the latest on your Airhead? Do you still like it? Seems like the urine reservoir would need constant dumping. Would you consider plumbing it for overboard discharge if it was legal? I'm considering making the conversion to composting head to gain room for a water tank in place of the holding tank. Eliminating odors and hoses would be great too.

I added a small fresh water tank to flush the toilet and reduce odor. http://careandfeedingofnordicstarpartii.blogspot.com/

best upgrade ever, no problem emptying liquid tank, no need to plumb overboard. The only issue is that it can not be used when heeled on a starboard tack since the liquid will not drain into the tank resulting in a tack to pee on longer journeys.

That's pretty funny about the starboard tack. That's the first time I've read that and it makes perfect sense. I have yet to read a horrible review or one that doesn't sound like user error isn't more to blame.

The added fresh water tank would help with odor, but I'd rather not add more tankage just for the head. I'm looking to add more potable water capacity.

the better option would be to move the fuel tank to the holding tank location and add freshwater bladders under the midships port and starboard bunks for much needed extra balast when sailing single or double handed as I do.

another fact to consider about a conventional head+holding tank is that probably 75% (if not more) of what goes in there is seawater needed to flush the head, the composting head has therefore far more capacity and produces a byproduct that will make everything in your garden grow like it is on steroids!