I have had my 340R (K Engine.. but 190HP).. I would personally go with Toyota engine... Maybe it's something to do with me being in Japan and having so many aftermarket parts available. But also to do with the situation with Rover. The reliability is not compareble to a Toyota engine. the difference in price is just too much, though.. for that price I guess I would go with the Rover one.. I guess it's little different as you can get parts readily in the UK.
340R 72/340 - Black metallic, 190HP upgrade, Exhaust manifold heat wrapped, Custom exhaust w/ Metalic cell cat, Aragosta alum. Coil over suspension, ATS carbon LSD, All aluminum radiator, 82degC thermostat, Iridium spark plugs, short stroke shifter, Red & Carbon Carbon fiber seats(awesome), 55W HID w/ new lens housings, Neova AD07. Carbon fiber disk brakes & pads(proper caliper not mounted, yet...agh)
1992 R32 Skyline GT-R - GT2530TT and parts to follow -600~HP? daily driver.