we have plenty of sulfur in this area. i've used and installed several different systems. most common here is simple aeration. in the last couple years my favorite systems are the ones that oxidize the sulfur under pressure, i really like the odor oxidizers from www.aquatechnics.biz as i've sold several and had one on my house for over a year now and had 0 problems.. and if you call cracking a drain valve once a year to run off the sulfur collected at the bottom until it clears maintenance, then i guess it has a tad. however, this being a vacation house, i might stay away from any system that stores water in a tank. i usually wouldnt recommend this type of unit for every day home use, but i've been made to install one or 2 by customers and they seem to work pretty good. http://www.water-right.com/residenti...on_filter.html the ims filter might be your best bet for a vacation house. little to no maintaince, no storage tanks, uses air only to remove sulfur.
there are a few peroxide systems around here and they do work well, but i'm not a fan of upkeep and maintenance, and those require you to keep buying peroxide. i cant justify buying a product to remove sulfur when air is free and seems to be the best solution for it. just my .02
btw, softeners arent really meant to treat sulfur.. and you might find your water is ok for vacation usage by using some type of in-line filter like you mentioned. i cant help you there, i stay away from those types of filters and am clueless when it comes to them.. other than knowing you better have a few extra cartridges laying around as they clog up pretty regularly and always restrict volume and pressure.