welcome! yeah the pegs and rear seat are sold as a set from Honda, but like TS said, you can probably find one or the other on ebay or elsewhere now.
i have read negative reviews on here about the zeed seat (from a comfort standpoint). as far as the company goes, i've bought from them and had a good experience.
I have a corbin seat on order, this will be my 2nd one overall on any bike i've had, and they are amazing. i might go so far as calling them the gold standard of aftermarket seats.. but of course that's a matter of opinion.