people normally get shitty when we suggest the search feature of the forums, but its really handy. there is a thread in the faq section regarding nissan engine model numbers.. basically the prefix (in your case CA) is the engine family, the numbers in the middle are the displacement and the suffix (in your case E) refers to cams & ignition etc.. so a CA20E is a CA series engine which is 2 litres & has electronic ignition.
as far as mods to your car goes, go the usual pod filter, extractors, exhaust & then throw in a cam too.. that'll get you around the 90kw mark, possibly more up from your stock 79kw.. after that look into an aftermarket chip, such as a power chip.. all up that'll easily chew thru your $2k.
as for leads, see if you can get top gun 8 or 10mm leads.