The fact of the matter is that practically any decent recent laptop will do a great job for you. Just spend as much as you need but there's no need to buy the latest and the greatest. Unless you're setting up a pro studio, any good off the shelf lappy will do the job just fine.

I actually did a similar thing to what you're considering. When I decided to get back into digital recording after OS upgrades killed my first studio, I bought a nice laptop, an interface, and speakers to get set up right. That was back in the day when even the cheapest laptops were not cheap. BTW, that laptop runs Windows ME and is still totally functional and gets used on occasion. I later built a desktop that I still use as my main DAW daily.

I'd seriously look into getting a nicer USB external musical interface and stop trying to use the built in sound card on the laptop. The realtec cards are not designed to do what we do. Spend a couple hundred dollars on a nice Presonus or Focusrite and do it right. You need a card that runs native ASIO, has a minimum of 2 inputs with low and high impedance jacks, phantom power, and the outputs you need.

Have fun.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.