Second what the guy is saying above. I'd look into a P90 plus model from Tokyo Marui. They are unbelievably good stock and need nothing doing to them. Deadly accurate and surprisingly good with range. Most magazines fit them so you could get the krytac mags to take 200 rounds but there is another well renowned brand of magazine (sorry I can't think of the name) that holds 140 bb's and they feed absolutely brilliantly and cheaper than krytac ones, if you can find them in stock. I can't speak for the krytac ones though so they maybe just as good!.
Obviously the TM doesn't have the adjustable trigger like the krytac has but it does come with a Marui mosfet so it is snappy by P90 standards and was comparable to the krytac, I can only assume that the trigger wasn't set on the guys I tried? So again, don't take my word for it on that. The overall experience though just seemed somewhat the same as my 90, for something that costs more for a few extra features. Maybe I'm being bias?.
I think if you're looking for reliable fun then the TM, you can upgrade it if your really want to but honestly, it needs nothing.
Krytac is a very good brand, don't get me wrong but the parts for them being there own can make upgrading it a bit of a pain I'd imagine. If something was to break too, I'd assume it's the same story. If upgrading it is something you want to do, don't bother with the krytac as it's just extra money for a shell and you might as well find some cheap cybergun one because you're just going to gut it and change all the internals anyway.
But, the choice is yours and you get whatever makes you happy!