Armor dropships are going to have more health overall and be able to take railguns and forge guns better, but only slightly so. They also are less effective at tanking swarms. The thing is that rails and forges you need to dodge, and swarms you need to outrun. Given the armor tanking, these dropships are very sluggish. This build, I've probably flown a Myron twice, and it felt like flying a boat. I'd hate to see how an armor tanked normal dropship handles.

So, I'm a big fan of shield tanking. I use the Python, the Caldari Assault Dropship. I like to fit it as follows:
High Slots:
Azeotropic Shield Extender x2
Ward Shield Amplifier
Clarity Ward Shield Booster

Low Slots:
Complex Turret damage mod x2 (can't remember the name)

Turrets:
These really come down to personal preference. If you want blasters, you're gonna have to sacrifice damage mods, but you'll probably be better at killing infantry.
Proto Fragmented Missile Turret x2 (in the left 2 slots, door gunners like this one for shooting infantry)
Proto Accelerated Missile Turret (in the right slot, I like the quicker missiles)

Stats:
2571 Shields*
~3024 Effective Shields*
Turrets do 18% extra damage per shot @ ~9.3% increased firing rate (~30% more DPS)

*All math in this post is purely from gear and factors in no skills. I'm also at work right now and don't have the time or resources to verify my math.

The Myron can be fit pretty much exactly the same, just ignore the front turret (obviously)

If you prefer blasters, you're going to want Local Power Diagnostic Units in your low slots (blasters are powergrid WHORES). I haven't tested blasters beyond the militia variant yet, so I can't give you any specific numbers.

Making it more tanky:
In my fitting screen, the fit shown above is named "Gunship" because it's designed to be an attack platform. However, if you'd like to make your ship more tanky then there are some changes that can be made. First, Local PDU's in your lows. I'm gonna throw some math at you.

All stats that say something like "increases your vehicle shields by x%" increase the base shields of your vehicle. Meaning if you have zero shield extenders or 15 shield extenders on it, it still increases it by the same amount.
Python:
1075 Base Shield * ( 1 + 7% (Local PDU) ) = ~1150 (+75)
1075 Base Shield * ( 1 + ( 7% + ( 7% * .85 (stacking penalty) ) ) ) = ~1215 (+140)

Eryx:
1700 Base Shield * ( 1 + 7% (Local PDU) ) = ~1819 (+119)
1700 Base Shield * ( 1 + ( 7% + ( 7% * .85 (stacking penalty) ) ) ) = ~1921 (+221)

Now if we add on our shield extenders:
Python:
1215 + ( 748 * 2 (Azeotropic Shield Extenders) ) = 2711
1215 + ( 748 * 3 (Azeotropic Shield Extenders) ) = 3459

Eryx:
1921 + ( 748 * 2 (Azeotropic Shield Extenders) ) = 3417
1921 + ( 748 * 3 (Azeotropic Shield Extenders) ) = 4165

Now we factor in resistances. Note that if you have 3 shield extenders, you don't have a slot for a resistance mod.
Python:
3 Shield Extenders: 3459 Shield HP
2 Shield Extenders: 2711 * ( 1 / ( 1 - 15% (Ward Shield Amplifier) ) ) = 3189 Effective Shield HP

Eryx:
3 Shield Extenders: 4165 Shield HP
2 Shield Extenders: 3417 * ( 1 / ( 1 - 15% (Ward Shield Amplifier) ) ) = 4020 Effective Shield HP
So, as you can see you will have a bit more health by running 3 shield extenders. However, shield extenders are VERY expensive in powergrid. So, if you'd like to gear a ship purely for defense then you should have 3 shield extenders. If you'd like a ship that has some free powergrid for attacking things, go with a shield amplifier.

Lastly, a thing about resists. The cool thing about resistances is that your Python will take damage like it has 3189 shields, but it only needs to repair like it has 2711 health. With 3 shield extenders, your shield repper will need to top off that extra 748 health. This means that a gunship can stick in the fight for a little longer because it will rep a higher percentage of its effective health with each cycle, but a defensive ship will have more health to run away with.
TL;DR
Defensive Ship: 3 Extenders + Booster + 2 Power Diagnostic Units
Attack Ship: 2 Extenders + Booster + Amplifier + 2 Damage Mods
Balanced Ship: 2 Extenders + Booster + Amplifier + 2 PDUs

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Gah, it combines all my posts into 1... Sad Added a line of -'s for clarity

One more thing (that I don't want to get lost in the sea of text above), the modules are more important than the ship. If you have an assault dropship in militia modules, prepare to lose a lot of money. Acually.. Prepare to lose a lot of money in general. It took me about 6 million SP to get all proto modules and the assault DS, and I've just got Assault Dropship Operation level 1 (which getting to that is like 3 mil on its own). It's FAR more skill intensive than it used to be, as I was a Type-II MH-82 heavy w/ proto shield mods and a proto modded Myron last build, and now I'm just a DS pilot.