Well, the obvious is that you'll need the fairing kit, mirrors, fairing stay, gauges/trim bezels, and either the entire rear fender/taillight/signal assembly, or the taillight and a fender eliminator kit - the one on my street F2 is from Competition Werkes.
So if you go original, you'll need EVERY part in these fiches:
REAR FENDER ,
http://www.ronayers.com/TAILLIGHT-C186674.aspx
#'s 10, 12, 16, 17, 18, 19, 20, 23 (18, 19, 20 & 23 - quantity of 2), in this fiche:
TURN SIGNAL - F2 - 91-94
and #'s 2, 5, 6, & 7 (6&7 quantity of 2), in this fiche:
SEAT
The above listing will be
quite pricey, so eBay, Craisglist, forum sale threads, etc., will be a life-saver there.
If you are able to score a fender eliminator kit, you can eliminate some of these parts, and will only need:
All items from this fiche
TAILLIGHT
Once again, #'s 2, 5, 6, & 7 (6&7 quantity of 2), in this fiche:
http://www.ronayers.com/SEAT-C186658.aspx
and you will still need the items included in #1, in this fiche
REAR FENDER
I can't tell from the pics, because they are a bit dark, but it looks like there's something else that's been removed, which are the brackets that mount on both sides of the motor, at the bottom, for completing the lower mounting of the large side fairing panels - if these are indeed gone, you'll also need: #'s 4, 5, 20, & 21 (20 quantity of 3) in this fiche
LOWER COWL - F2 - 91-94
A cycle salvage could also be a good resource for picking up these things cheaper.
Depending on whether you choose aftermarket or OEM fairings, there may be some other small items needed for mounting the inspection panels to the upper cowl and lower fairings.
Lastly, a word of warning: a lot of fairing stays that are sold used, have been pulled from wrecked bikes, so they may be bent - given what a lot of folks are asking for fairing stays, it might be better to just get a new one, which is number 15 in this fiche:
UPPER COWL - F2 - 91-94
It really depends on whether or not you can trust the seller, regarding the item being straight.