generally, a 17 footer isn't a prime choice for soloing - as much because of width as anything else.  any tandem can be solo'd, but not as well as smaller boats.

more commonly recommended are several boats referred to as "pocket trippers" - slightly downsized tandems that work better if you want to solo a tandem, as they are a bit narrower and lighter, but still capable tandems.   Mad River Malecite 16.5 (symetrical- that $3K ultralight looks sweet); Bell Northstar 16.5 (asym, but you'd have to find a used boat - solo from rear thwart position); Old Town Penobscot 16 sym (Ranger uses one as his do all boat) - Penobscot can't be had in composite though; Wenonah Solo Plus and the old Dagger Reflection 16 (Mad River makes it now, but its a bit different boat)

a lot of fans of soloing tandems on solotripping.com - Nova Craft Pal 16'  seems to be a favorite. 

And The Souris River Q 16 can be set up solo or tandem by adding a center seat.   The center seat option used to be offered for the Malecite as well - likely it still is, the old Reflection 15 came that way also, and the Solo Plus comes with that third seat. (they aren't really center, more aft of center, but not as far back as a bow seat would be)


the common theme, is a more or less downsized tandem that is better for soloing than a bigger tandem, giving up just a little bit of performance and capacity for tandem use

I've never solo tripped with a tandem, though I have paddled my Northstar and 15' Grumman solo - The Northstar had an option for a kneeling thwart, but mine just has a standard round tubing thwart - it solo'd ok from that thwart (I'd guess you could replace with a hung bench seat - if you could find one of the boats used), and the Grumman solo'd from the bow seat reversed.  Neither was good enough to make me use one instead of my solo boats, even for day tripping if I had an option.

you'd be a lot better off with two boats (buy used and get two for the price of one) and just squeeze them in the garage somehow - I have one boat hun up over my F150 with about 3" of clearance, and I don't have a very high garage.