There are 3 classic builds for mandalorian, depends on what your gamestyle is
1: Classic Assault
westar 3
ee3 0
fuel 3
flamethrower
rocket
armor 2
ammo 2
this is most common build, because it has a bit of everything. westars are really accurate and you can almost snipe with those two, rocket is great diversity and flamethrower gives u breath when full force jedi rushes on ya. + fuel 3 lets you use it for really long.
2. Sniper
Ee3 3
fuel 3
flamethrower
armor 1
ammo 3
Probably the hardest build to hit score. It bases on your sniper and quickscope skills. You have some fuel to play seek and hide with jedi or fry them, but you mostly take down enemies, when they're busy fighting your mates (disturbing duels and shit), you also depend a lot on quickscope in 1v1 with jedi. you shot one snipershot and if it lands, you continue with spray. You have to remember that after 3rd shot ee3 starts to overheat and is inaccurate, even though it drains alot of fp.
3. Commando
ee3 3
fuel 2
flamethrower or wrist laser
armor 1
ammo 3
You have to be really careful with this build. You don't abuse jetpack, because you have low fuel and you'll need it both to run from jedis and to fry them (if u pick flamethrower. this is why some ppl take wrist laser even though it really sucks comparing to flamethrower). So when theres no enemies nearby, you just act like theres no jetpack, and run. Good thing about this build is: you have every 3 diversion item: rocket, sniper, flame/wrist what might safe your ass in many situations. You can use rocket to shot group of jedis while they're togethere in corridor, very close to eachother / set up traps / fry and quickscope them, sniper-disturb duels or just snipe from hideout.
of course there are builds with flamethrower and wrist laser, but its really hard to toggle between them (you can't do it while holding ee3 / westars, you have to switch on melee and then hit weaponmode - it takes loads of time). In my opinion those specials would be awesome, if toggled as quick as ee3->sniper. but unless you have to switch to melee, this build wont work at all.
and if you have dilema between flamethrower and wrist laser, pick flamethrower. it breaks through full force jedi, starts burning effect, drains loads of hp and doesn't require as much aim as wrist laser. remember theres a lot of situations in mb2 when you won't have time for precission shots and opponents will make you react instant.
you also have to be smart while using flamethrower. it drains your fuel and its unrechargable, so once you lose it, you wont get it back. its really important, because throwing flame at jedi who's too far is just a waste. if you cant see jedi frying / running from dmg, stop flaming and throw some close-shots to control his force points.
to be honest, mandalorian is one of hardest class around (unless you fly and jihad stuff) vs skilled jedi (puller, speeder), but its also fun though. and its really easy to fight newbie jedis, coz they mostly can't get through your flame. don't get discouraged, train.
hf: )
p.s
in my opinion first build is good for start, second build is good for open maps like dotf, and third build is good for close combat maps like deathstar