I need a laptop with 4 memory slots ( i.e that can handle 32 GB RAM ) ..
I am look at Dell or HP made ones . I will not buy the laptop with all 32 GB filled in , but will buy the default cheaper option and pop the 8 GB RAM myself .
No specific recommendation, But:
1) On Ram, Not sure what you mean by HIGH end. Most likely you will be limited to DDR3-1600. Reason - A) Laptops normall have a LIMITED (locked) bios so that you can not go in and change the speed/timings B) For Ivybridge CPUs the spec is DDR3-1600 (Sandybridge was DDR3-1333). C) Little known fact, Using Ram above DDR3-1600 VOIDs Intel's CPU warrantee. Might find Custum built with Higher ram speed, But that would still void Intel's warrantee, but who you bought it thru would probably cover it.
2) I had a Dell Laptop, on 24/7 2008->2013 was still going strong which was replaced with a HP. Both are considered a Desktop replacement and are their Enterprise Models (Not cheap). However there consummer models do not fair that well, HP being close to the Bottom of the barrel for reliability/least user problems.
My choices in laptop brands are limited to Asus, Toshibia and Samsung.
3) Add to your requirements 2 HDD bays. One for a FAST SSD (by with a HDD, replace HDD with SSD and move orginal HDD to 2nd Bay. NOTE: My 2nd laptop at work came with ONE HDD bay Plus a HDD mounted in a DVD enclosure so that it could be swapped out with the DVD drive ( they also provided a USB DVD Drive).