John, if you must have portability, you will do well with the Hobart unit. My brother has one on each of his boats (he runs a tender service between Seattle / Ketchakan / Kodiak and points between) Even after constant exposure to sea spray they still work when called upon for repairs.
If you are primarily going to use it for repairs and you don't have a time constraint on the welding that needs to be done the 30% duty cycle is fine.
We just bought a Millermatic 225 for work. 230V single phase feed - 165 cu ft bottle of gas, light sensitive welding hood (thrown in for free) an extra spool of wire .035 double shield . . . out the door for under $1700.00!
If you can find what you want at a local welding supply place - make a friend, strike a deal and you will have a lot better support down the road.
