Hey Bud, good on you for saving up a deposit for a great car in the R32 GTR.
Some things to be weary of is that they are getting on in age now and cost a mint in maintenance and or repairs. Essentially, unless you are willing to pay top dollar for a top condition one or already rebuilt one, be prepared to do the rebuilding yourself.
The upfront cost and heritage of the R32 GTR is very appealing these days, but the ongoing costs can be a big hinderance.
Without trying to generalise, I would say few to none of the 18yr olds I know would have a budget that would afford to run a R32 GTR.
My suggestion is continue driving your VL (without wasting money on modding it) and save your bickies up for a few years time (when it is probably legal to drive a turboed car) and you can then enjoy what it's like to drive a R32 GTR and the responsibility of owning and maintaining it. Sorry for sounding like I'm trying to steer you away from owning a skyline, but owning a car of that nature comes with both pro's and con's.