250F or 450F

What bike would suit me 250F or 450F and what brand for reliability? Here are some of my requirements:

1) It must have Electric Start

2) Needs to be lightweight like my 2-stroke.

3) Need enough power to hall my 5’9”, 205lbs around. (I will hopefullybe around 190lbs hard soon)

4) Reliable, this is very important, I don’t want to have to deal with valve problems.

5) Needs to be a good bike in the technical stuff and good hill climber.

6) I am a social rider and do maybe 2 or 3 races a year tops.

What do you guys think of the WR250F? Will the power be enough.

Wouldn't the KTM450XC-W be better for trail riding, I know it is heavier, but the other is an MX bike. How do the MX 450's do as technical trail bikes. KTM 450 SXF having electric start would be a big advantage over all other 450 MX bikes.

I know it sounds dumb considering I ride a 250 MX bike as a trail bike, but I have come to this conclusion lately, if you want to do MX get a MX bike, if you want to do enduro's get an enduro bike. I think what has put me off converting MX bikes to enduro bikes is that the 1st gear is to long for the really technical stuff and the power is a bit snappy.

This is partly why I have considered looking at a 250F, less power and smoother power than my KX, I do most of my riding in 1-3 gear so top end isn't the most important thing. The main thing is that it must handle slow technical trail riding well and that the bike must be super reliable. Good bottom end grunt at low rpm is important.

Do I look at the KTM enduro range of 2-strokes or is the answer a 4-stroke of any make?