Well, its a 19" 1998 Clockwork - looks nice to me
To address a couple of your points, if you want a nice saddle I'd go for a Flite but if you want a cheaper one then a Charge Spoon one are pretty popular for about £20. Put an ad out for an Orange saddle in the 'Wanted' section of the forum if needs be, sure someone'll have one for sale sooner or later.
Tyres, I'm a sucker for amberwalls so Charge to the rescue again although I appreciate you've just bought a new pair.... but Splashback tyres on ebay for £9.99 each delivered which is a bargain (I've just got some!) - size 1.8 would suit your bike IMO.
Forks, keep the originals or if you want some bounce - Pace RC36 would your best best, 100mm travel max probably. Think yours will be 1 1/8" for a '98 as opposed to 1" previously, but someone will confirm. I'm no expert.
Perhaps a low riser bar (Orange Supercross) and ditch the bar ends as well? Raise the seatpost up so looks better proportioned unless its a touch too big for you? SPDs, too?
But it's all upto you of course......
1990 Ridgeback 704XT 1990 Raleigh Dyna-Tech Encounter (SWMBOs) 1992 Orange Aluminium 'O' 1992 Orange Prestige 1994 Orange Clockwork 1996 Orange P7