I have been running with Progressive motorcycle insurance for 4 years now, and while I haven't had to put them to use *knocks on wood* they have always been cheap and simple to set up. I pay $130 a year for two old Honda CX500's. It is just a touch higher than minimum coverage, but they include collision coverage (my bikes were dirt cheap, so I just left them at $1000 covered). That premium includes discount for 3 years no accidents, and 10% defensive driving course.I used to have Geico, which for me anyways was almost twice as expensive.
For NYS registration, your best bet is to walk in with
DTF-802 filled out, rather than a homemade bill of sale. They have been getting a lot more testy about other bills of sale, but they seem to accept the 802 in good form. If the bike is already yours, then you will need some form of old proof that it is yours (expired registration, etc). If it's your old bike AND you don't have any old documents... then officially there is no way to register it (ask me how I know...). The option that I took was to "buy" the bike from a friend. At least with your bike you don't have to deal with a title transfer! Make sure your insurance is valid and in effect when you walk in to register and title the bike, otherwise it's a no go. Other than that, bring a check to pay your tax to the man and it'll all work out.
EDIT: Forgot to mention, my bikes are 500cc cruisers, I'm a 20 something male in the greater Rochester NY area, hopefully that helps compare insurance rates.