There is no requirement to model basic wargear. As the combination of stuff that a chaos marine carries is referred to as ultra grit, you don't have to worry about modeling all the various bits.
Only the special/heavy/power/etc... weapons need to conform to the WYSIWYG rule.
Any of the combinations you listed would count. Heck -- you could have a bunch of marines with no guns and they would still count as having the basic wargear...
Personally I love this - I have many marines with Bolt pistols and close combat weapons, probably more than plain bolters, because it looks cooler. (IMO) They still count as having the Bolter.
Long story short, don't worry about it. Model the special weapons. Make the rest look cool.