I dont mean to be a knob jockey (It just comes naturally) but for £4.5k you could get a good car.
OR
If you really want a fast N16 you could do an SR20 transplant for less than 2 grand. Then you have a tuneable engine with 140ish bhp on tap. Or spend a bit more and stick an SR20VE in for 190ish bhp.
For about £1500 you could build a fairly good SR20 powered micra also.
You could get a 1.4 almera equation N15 and stick an SR20 in, or de-gti a red N15 GTi with bumpstrips, plastic bumpers, spoilerless bootlids, for pennies.