Actually, other than the bike, you don't need ANYTHING!
You don't need to provide a UVIP. That is optional. NOWHERE in the HTA does is say it's mandatory for you to provide one. You do this as a courtesy to prospective seller's to show you are a somewhat responsible seller. Even the MoT paperwork does not say it's mandatory. So this is up to you. If you want to spend the time and money then go for it. MYSELF personally, I always provide a UVIP and always ask for one. If the seller does not have one then I move on right then and there. In my books, if they are clueless about what it is then they're probably clueless about numerous other vehicle-related things. If they're too lazy to get one then they're probably too lazy to do regular maintenance.
As for the safety certificate - same as above. Courtesy move, it's nothing else. As a seller you can use this as leverage, a bargaining tool. As a buyer, truly, it should mean nothing. You know how easy it is to get illegal safeties in Ontario?!?!?!?
Depending on the intelligence/experience level of the buyer, you don't even need to provide an ownership. (although this opens up a can of worms because they will be coming back)
I would like to add that you spend some time looking at your competition. Prior to listing you ad, for anything, spend some time (hours, days, weeks, whatever) and familiarize yourself with what average asking prices are and see if it's in-line with what you expect. Asking 75% of msrp on a 5 year old bike might not get you many emails/calls.
Good luck.