a few diffrent questions

I having the engine removed and refreshed over the next couple of months, so I was just checking body work Iv found the inner rear archs sent the best, what's can be done new plates, inner archs?
So
New inner rear arches?
Where to get CP 86mm piston rings
Where to get a new oil pump
What updated headgasget to use? (Block head has had no work done to it just forged pistons)
It's had ARP rod bolts fitted
While I'm there do I get hks cams??

inner arch is quite easy for a decent fabricator to make up repair panels, you could also look at buying the standard n14 inner arch panels & cut them into repair sections perhaps .
http://www.carz2.co.uk/nissan-sunny-n14-sedhb-91-95-mudguard-without-reinforcement-repair-panel-left-rear-kk1628555-96441-p.asp
http://www.carz2.co.uk/nissan-sunny-n14-sedhb-91-95-mudguard-without-reinforcement-repair-panel-right-rear-kk1628556-96442-p.asp

FR sport have oil pump & expect you could get cp rings from them too all in one order.
http://www.frsport.com/Nissan-13500-54C00-Pulsar-GTi-R-GTiR-SR20DET-Front-Timing-Cover-Oil-Pump-Assembly_p_1798.html

I would go with cosworth gasket & be sure head & block nice smooth finish, victor reinz gasket not bad quality or price for more standard lower power builds.

Cams come down to what you using/building car for, what power & what condition your current ones are in. If you got standard cams in A1 order & use car for road the standard cams are good, I would look at some porting work to head, standard exhaust manifold & a 3" elbow. HKS & Tomei do good cams if you need them for your build .

Ok thank you, as for engine it's running the reason for refresh is the low compression 125psi across all cylinders and I made a repair to the big ends as it had spun a bearing but got away with it but now it's being taken out I want to get the crank checked at the engineering place and most likely ground then replave the cp piston rings and update the head gasget too, the cams are standard and seam ok the plane Is for 350 and up to 400 max road use maybe a little track use