A 458 would be bottom of the market at that price, plus I'd want the Spider. So no Fezza.
A 991 Turbo would be staggering performance, but 4WD? No thanks. So no Gallardo or R8 either.
540/570 are too ugly, and you won't get many options for your £150k so nope.
I'd want something that made me feel special, but that I felt comfortable spanking the arse off of. If we're assuming this isn't a lottery win so I can't replace it the next day if I bin it, then I'm going to pick one car that's track friendly but not road unfriendly, it has to make a nice noise, and it has to be affordable to run. Must be showy without being flash, must be premium but not poncy. Above all, it must reward as a driver.
ONE CAR CHOICE
991.1 GT3, in Racing Yellow.
On the basis you cannot buy a 991.2 GT3 even if you have the cash, I'll take the earlier car. 9k rpm, 475bhp, flappy paddles but at least I know I like flappy paddles in 911s, and it would have to be the Clubsport model. Available from about £135k.
TWO CAR CHOICE
Exige Sport 380.
For me a track car must always have the option of a roof, and Lotus make the best tin-topped track cars so here you go. I've never drive of these, however we all know it's bloody superb. £70k I reckon with options plus a haggle.
997.2 GTS, in Basalt Black. 2WD manual option.
Still the best car I've ever owned, and for the road I don't need anything else. Perfect size, balance, weight, power, seats. The one car that does it all, I would find room for again in my collection. Truth be told I'd buy it again tomorrow if I had £60k spare.