Depending on the available space, installing a VacuFlush head as an aftermarket installation on a 32 foot boat could be a little "iffy."
The VacuFlush head, in addition to the actual toilet in the head compartment, has a vacuum generator unit that must be installed somewhere below deck, between the toilet and the holding tank. It is roughly 18" tall, 12" wide and 24" long. Plus, you need additional space around it, to plumb to and from it.
The vacuum generator evacuates the hose between the toilet and the vac generator and holds it constantly under vacuum. When you step on the foot pedal to flush the toilet, a ball valve opens in the base of the toilet, breaking the constant vacuum, which sucks the contents of the toilet out and draws it into the vacuum generator's tank. When the vacuum level in the line drops, the vacuum pump comes on. While the vacuum pump is running, it performs a dual function: 1) it pumps out whatever is in the vacuum tank from previous flushes and sends it off to the holding tank, and 2) it evacuates the line between the toilet and the vacuum generator, in preparation for the next flush.
They tout that their system will flush with as little as a pint of water. Yes, if you just #1 into it. But for solids, it takes water to carry the effluent to the vacuum generator. The vacuum won't do it by itself. In practice, in order for it to flush properly and not have the waste splatter all over the inside of the connecting hosing and stick to the inside of the hose, it takes more like a quart and a half of water.
One bugaboo with the VacuFlush is that if installing a new system, it must be installed by one of their certified technicians. Or if you decide to self-install it, the installation must be checked out and approved by one of their certified technicians - or they will not offer any warranty coverage on it. Depending on the boat's layout, a single VacuFlush toilet installation will usually cost you somewhere between $1800 and $3000, with it generally leaning toward the high end.
You'd have to contact SeaLand/Dometic's midwest regional distributor to arrange purchase of the equipment and also to arrange for the installation. SeaLand/Dometic does not sell directly to the public and you won't find their systems in a marine store; their sales are all through their own distribution network. Occasionally you'll find replacement parts for some of their stuff in a marine store, and on Boatfix, but not a complete new system.
I don't want to spend your money for you, but as a possible alternative, have a look at the Raritan Marine "Elegance" line of toilets. They work equally well, use about the same amount of water, and cost a good deal less - plus, you can install one yourself without worrying about losing your warranty coverage on it. Get the "poop" on them from Raritan's website, then check with BoatFix for pricing.
http://www(dot)raritaneng(dot)com/products/toilets/electric/marine_elegance(dot)htm
http://www.boatfix.com/shop3/store/listItems.asp?strSearch=Marine+Elegance
It was suggested that you try to pick up a late-model used VacuFlush system. If you choose to do that, BE CAREFUL, to be sure you get ALL the components you need, and that they're all functioning properly. It's very easy to get "stung" when buying a used head system of ANY type or brand.