Oops, I thought you were buying a GT AND a 159.
So do u need a very good looking motorway cruising load lugger, spacious cabin, lots of camping trips, kids, bikes etc. If so maybe the 159.
Or can u use a 1.8, maybe there's not much load unless you're lugging amps and speakers around. U have a 1.6 already so you prob know if it's loaded up, it's not going to overtake too well or stop too well, but it will be a hoot on country roads and if you're the sort that risks doing 15 mph over the motorway speed limit, it'll be a smooth cruiser.
My advice if u have 15k kicking around?
Buy a 5k V6 GT with good history, keep 2K back for a Remap, Pirelli PS3's, Koni FSd's, Eibachs, strut brace, new wishbones all round topped off with a BMC CDA for a nice bit of cabin music.
I love the 159 and will have one to replace the 156, but the cabin on a GT is so much nicer for a driver IMO and the V6 is something that everyone should experience.
Red GT cloverleaf is an incredibly good looking car tho. I remember the first time I sat in a red GT cloverleaf at the dealers, I honestly felt like they'd made the cabin especially for me.
Have fun in your quest, don't stress.
Lost wifi connection so didn't see you'd answered some stuff already