I would say alot of time it doesn't matter what brand gun you get, but its luck. I have been running a stock AGM 416 for 2 years + now, and I see other peoples upgraded/high end guns break all the time. I would say, if your willing to invest time into your weapons, take care of them, and have inside work done by a professional, you should be okay majority of the time.
You say you have a unique taste, No M16, no AK, and no G36. There are plenty of other options-
AUG (most recommended model would be the A3 by JG)
SIG (ICS, G&G, theres a TM one up for sale for cheap cheap from quadro)
MP5 (ICS, G&G, TM, CA, and more)
Galil (ICS, KA, CYMA)
FN2000 (G&G)
Type 89 (TM)
the list goes on.
On places to play, and play style, if your looking to be a sniper with a bolt action rifle, come to TAC games. But you will need to learn patience (which is something I don't have, which is why I don't snipe), concealment techniques, and where the best spots are at each opsite, where a stray bush/branch will not knock your bb off target. PM Ben about this, hes an experienced sniper (whom I have been shot by many a time) and he will show you the ropes.
If you take a ZL mosin-nagant to Toxic or DP, you will be laughed at, and then sprayed. Taking a sniper rifle to one of these places is plastic suicide. I feel that once you have played at either place once, you will understand what I mean by this. At TAC however, our play style suits and allows for snipers to have an important role in gameplay both in and out of combat.
In modern day, especially in airsoft, a snipers primary weapon is their scope (or binocs) and their radio. They are essentially stealthy, lone recon units when taken into consideration of the grand scheme of a large event game. The sniper rifle is secondary, only to be used when absolutely necessary, again this is airsoft, a single unit cannot be held at 700m, AEGs close the gap against 1000$ + sniper rifles very quickly, even in mil-sim.
Your question about side arms-
Yes you will want one. I run assault rifles mainly and I even have one that I carry during event games, its an AEP. A sniper will want a more hard-hitting and faster firing weapon. KWA and other top brand gas pistols will do the job well, as with an AEP the bb flies slow enough for someone to dodge matrix style at max range!