Under what circumstances would you need to get dressed up like a SWAT cop or soldier? What survivable scenario couldn't be handled with the rounds in an AR and maybe a "backup" pistol?
If really think you'll need all that stuff, have you considered putting it on some kind of hard armor instead of an easily-ventilated vest? I mean, if you plan to launch that much outgoing lead, there's probably a really good chance that there will be some incoming fire, too, right?
A good kevlar helmet is probably a good idea, too, if you plan on an extended, high-volume firefight. With the Army switching to the ACH, you can likely find a good deal on an older surplus PASGT helmet.