welcome.
oil temp, oil pressure gauges hard to fit? Get a pro to do, it involves routing wiring etc, can be done DIY but you need to be good with the spanners
injectors what cc is the best upgrade ? wont need to of your targets
does fuel rail/pump need upgrading ? fuel pump is needed, walbro 255 or equivelant
worth upgrading to 10mm ignition leads iridium plugs? ignition leads nope, plugs yes, pf7's
also does anyone know a reputable gearbox re conditioner or would you suggest just gambling on buying a box as she has a grind into 4th when giving her death. I use scoobyclinic for all my work.
is a electronic boost controller worth the gamble? or not worth it until turbo upgrade? nope, ecu controls the boost, no need even when upgrading the turbo
best time for remap ? (after fitting what parts?) yes, no point in mapping then fitting parts as will need the map tw3eaking
turbo timer worth it? nope, just drive it steady last few miles before you park up, much better for the car as it keeps fluid circulating so they cool evenly
hope that helps :)
p.s.. your limit is going to be the turbo, anything over 260 is a bonus.