Are you going to be mostly travelling alone or with a passenger? I have a lowly 130bhp K-series, which on my own, feels like about all the power you need on the road. Even with the 6-speed box I've driven to the Pyrenees, Alps, Dolomites and do 3 or 4 track days most years (driving to/from them, including a couple in France) and it's fine. Where it feels "slow" is when I'm 2-up, and I'd definitely want more power if I was regulalry having a passenger.
If you want to enjoy sliding the 310 around, just go for 6" rear wheels and fit some less grippy tyres. I've always run road tyres on mine, even on track days, and find there's much more fun to be had with slow-car-fast. It also reduces wear and tear on consumables.
I bought my first Seven and kit late Oct 2018, it was a 420 after upgrading it from a 360 because of the desire for a dry sump and the added clearance. I haven't regretted the decision. That said, I would always say buy the best you can afford based on your budget, everything thing else doesn't really matter.
Go and have a look at the second hand cars, you will see that the higher powered variants almost always have lower mileages. Go for the smaller lighter Sigma engine and you will save money which can be spent on Track Days or Touring and get a more drivable car.
I have what at the time was the least powerful Seven a 1.6K SV. Eighteen years later while I have upgraded various aspects of the car I still have not bothered to touch the engine. The car has done numerous track days and been to the Alpes a number of times. The fun bit on Track is for me the corners and it is not lack of power which makes a driver slower round those
1.6K Roadsport SV
As far as engines are concerned all I would say is that you can drive a 200+ bhp car like it is a 150bhp car. It doesn’t work the other way around.
But why do you want the R pack if you're not going on track regularly and you intend to tour? I see nothing in there that will not make that kind of use less comfortable.
A 420S would be my choice for that profile. You could always get an LSD fitted later, if you felt like you needed it, and avoid the Titan trap into the bargain.
I tried (on the road) the 310, 360 and 420 and preferred the 310, felt nicer to drive.
Ended up buying a 420 but I think I would have been happy with any of them.
Orange is my new black
I initially went in to Oakmere after doing my research with the specific intention of buying a 310.
3 hours later I had signed my order form for a 420R, pretty much for all the reasons you have mentioned.
Budget was well and truly blown which hurt at the time but have never looked back and am glad I did it.
#17. I thought the Sigma cars had the 3.91 diff not the 3.64? Maybe not.
420 also has 3.91
Ah yes, the 3.64 was only with the 6 speed, wasn't it?