I haven't spent much time inside a Yamaha to know how roomy it is. I went with the 207 for a similar reason, that is is more boat for similar money.
As for financing/payments, I really don't see much of a difference between $286 and $298. My payment is in that range, and I also put $0 down.
Having some experience with Yamaha skis might make you more familiar with their engines and maintenance. The Glastron has a closed cooling system for the engine, which I would prefer for the salt water (but still open cooling on exhaust so you would still need/want to flush). A little additional maintenance there too with the supercharger rebuild (200 hours I believe).
Then you have the clean out ports. Most Yamaha owners seem to feel that this is a highly important feature. Never having one, I cannot comment that way, but I have not needed one in the past. I run typically inland lakes. Maybe the Hudson and ocean makes this a bigger issue?
If I had to throw out an opinion, and the others cam chime in, I think bang for the buck would be the Glastron. However, I would be willing to concede that the Yamaha would be a slightly "Nicer" boat. You would trade some size for some fit/finish and creature comforts. And not to add to the confusion, you might want to look into the Scarab, and I am sure
@ScarabMike would agree. This would be a cross between the Rotax power and the nicer "quality" (for lack of a better term) of the Yamaha.
No matter what you choose, I am confident in saying that you really can't go wrong whichever direction that you go. If you put your location in your profile, maybe there are some Yamaha owners in your area...